diff --git a/.eslintrc.json b/.eslintrc.json
index fa28720e17..d732833a39 100644
--- a/.eslintrc.json
+++ b/.eslintrc.json
@@ -192,7 +192,8 @@
         "common": false,
         "panels": false,
         "PerfectScrollbar": false,
-        "search_pill": false
+        "search_pill": false,
+        "Sortable": false
     },
     "plugins": [
         "eslint-plugin-empty-returns"
diff --git a/package.json b/package.json
index b066e394a0..7a83db60a8 100644
--- a/package.json
+++ b/package.json
@@ -33,6 +33,7 @@
     "plotly.js": "1.37.1",
     "sass-loader": "7.0.1",
     "script-loader": "0.7.2",
+    "sortablejs": "^1.7.0",
     "sorttable": "1.0.2",
     "source-map-loader": "0.2.3",
     "source-sans-pro": "2.20.2",
diff --git a/tools/webpack.assets.json b/tools/webpack.assets.json
index cc16675ca7..305545aaab 100644
--- a/tools/webpack.assets.json
+++ b/tools/webpack.assets.json
@@ -21,6 +21,7 @@
         "./static/js/common.js",
         "./node_modules/moment/min/moment.min.js",
         "./node_modules/moment-timezone/builds/moment-timezone-with-data.min.js",
+        "./node_modules/sortablejs/Sortable.js",
         "./static/third/bootstrap/css/bootstrap.css",
         "./static/third/bootstrap/css/bootstrap-btn.css",
         "./static/third/bootstrap/css/bootstrap-responsive.css",
diff --git a/version.py b/version.py
index 5299afa99d..8ea31acbb1 100644
--- a/version.py
+++ b/version.py
@@ -8,4 +8,4 @@ ZULIP_VERSION = "1.8.1+git"
 # Typically, adding a dependency only requires a minor version bump, and
 # removing a dependency requires a major version bump.
 
-PROVISION_VERSION = '21.0'
+PROVISION_VERSION = '21.1'
diff --git a/yarn.lock b/yarn.lock
index 426656c53c..9d05a32608 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1761,7 +1761,7 @@ chalk@^1.0.0, chalk@^1.1.1, chalk@^1.1.3:
     strip-ansi "^3.0.0"
     supports-color "^2.0.0"
 
-chalk@^2.0.0, chalk@^2.0.1, chalk@^2.1.0, chalk@^2.3.0, chalk@^2.3.2:
+chalk@^2.0.0, chalk@^2.0.1, chalk@^2.1.0, chalk@^2.3.0, chalk@^2.3.1, chalk@^2.3.2:
   version "2.3.2"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.3.2.tgz#250dc96b07491bfd601e648d66ddf5f60c7a5c65"
   dependencies:
@@ -1769,14 +1769,6 @@ chalk@^2.0.0, chalk@^2.0.1, chalk@^2.1.0, chalk@^2.3.0, chalk@^2.3.2:
     escape-string-regexp "^1.0.5"
     supports-color "^5.3.0"
 
-chalk@^2.3.1:
-  version "2.4.1"
-  resolved "https://registry.yarnpkg.com/chalk/-/chalk-2.4.1.tgz#18c49ab16a037b6eb0152cc83e3471338215b66e"
-  dependencies:
-    ansi-styles "^3.2.1"
-    escape-string-regexp "^1.0.5"
-    supports-color "^5.3.0"
-
 chalk@~0.4.0:
   version "0.4.0"
   resolved "https://registry.yarnpkg.com/chalk/-/chalk-0.4.0.tgz#5199a3ddcd0c1efe23bc08c1b027b06176e0c64f"
@@ -2107,16 +2099,10 @@ combined-stream@1.0.6, combined-stream@^1.0.5, combined-stream@~1.0.5:
   dependencies:
     delayed-stream "~1.0.0"
 
-commander@2, commander@^2.12.1, commander@^2.9.0:
+commander@2, commander@^2.12.1, commander@^2.7.1, commander@^2.9.0:
   version "2.15.1"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.15.1.tgz#df46e867d0fc2aec66a34662b406a9ccafff5b0f"
 
-commander@^2.7.1:
-  version "2.9.0"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-2.9.0.tgz#9c99094176e12240cb22d6c5146098400fe0f7d4"
-  dependencies:
-    graceful-readlink ">= 1.0.0"
-
 commander@~2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/commander/-/commander-2.1.0.tgz#d121bbae860d9992a3d517ba96f56588e47c6781"
@@ -3037,17 +3023,7 @@ error@^7.0.2:
     string-template "~0.2.1"
     xtend "~4.0.0"
 
-es-abstract@^1.5.0, es-abstract@^1.7.0:
-  version "1.10.0"
-  resolved "https://registry.yarnpkg.com/es-abstract/-/es-abstract-1.10.0.tgz#1ecb36c197842a00d8ee4c2dfd8646bb97d60864"
-  dependencies:
-    es-to-primitive "^1.1.1"
-    function-bind "^1.1.1"
-    has "^1.0.1"
-    is-callable "^1.1.3"
-    is-regex "^1.0.4"
-
-es-abstract@^1.5.1, es-abstract@^1.6.1:
+es-abstract@^1.5.0, es-abstract@^1.5.1, es-abstract@^1.6.1, es-abstract@^1.7.0:
   version "1.11.0"
   resolved "https://registry.yarnpkg.com/es-abstract/-/es-abstract-1.11.0.tgz#cce87d518f0496893b1a30cd8461835535480681"
   dependencies:
@@ -3113,18 +3089,7 @@ escape-string-regexp@^1.0.2, escape-string-regexp@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
 
-escodegen@^1.6.1, escodegen@^1.8.1:
-  version "1.8.1"
-  resolved "https://registry.yarnpkg.com/escodegen/-/escodegen-1.8.1.tgz#5a5b53af4693110bebb0867aa3430dd3b70a1018"
-  dependencies:
-    esprima "^2.7.1"
-    estraverse "^1.9.1"
-    esutils "^2.0.2"
-    optionator "^0.8.1"
-  optionalDependencies:
-    source-map "~0.2.0"
-
-escodegen@^1.9.0, escodegen@~1.9.0:
+escodegen@^1.6.1, escodegen@^1.8.1, escodegen@^1.9.0, escodegen@~1.9.0:
   version "1.9.1"
   resolved "https://registry.yarnpkg.com/escodegen/-/escodegen-1.9.1.tgz#dbae17ef96c8e4bedb1356f4504fa4cc2f7cb7e2"
   dependencies:
@@ -3223,7 +3188,7 @@ esprima@^1.0.3:
   version "1.2.5"
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-1.2.5.tgz#0993502feaf668138325756f30f9a51feeec11e9"
 
-esprima@^2.6.0, esprima@^2.7.1:
+esprima@^2.6.0:
   version "2.7.3"
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-2.7.3.tgz#96e3b70d5779f6ad49cd032673d1c312767ba581"
 
@@ -3261,10 +3226,6 @@ esrecurse@^4.1.0:
   dependencies:
     estraverse "^4.1.0"
 
-estraverse@^1.9.1:
-  version "1.9.3"
-  resolved "https://registry.yarnpkg.com/estraverse/-/estraverse-1.9.3.tgz#af67f2dc922582415950926091a4005d29c9bb44"
-
 estraverse@^4.0.0, estraverse@^4.1.0, estraverse@^4.1.1, estraverse@^4.2.0:
   version "4.2.0"
   resolved "https://registry.yarnpkg.com/estraverse/-/estraverse-4.2.0.tgz#0dee3fed31fcd469618ce7342099fc1afa0bdb13"
@@ -3456,14 +3417,10 @@ extract-zip@^1.6.5:
     mkdirp "0.5.0"
     yauzl "2.4.1"
 
-extsprintf@1.3.0:
+extsprintf@1.3.0, extsprintf@^1.2.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.3.0.tgz#96918440e3041a7a414f8c52e3c574eb3c3e1e05"
 
-extsprintf@^1.2.0:
-  version "1.4.0"
-  resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.4.0.tgz#e2689f8f356fad62cca65a3a91c5df5f9551692f"
-
 falafel@^2.0.0, falafel@^2.1.0:
   version "2.1.0"
   resolved "https://registry.yarnpkg.com/falafel/-/falafel-2.1.0.tgz#96bb17761daba94f46d001738b3cedf3a67fe06c"
@@ -4497,10 +4454,6 @@ graceful-fs@^4.1.11, graceful-fs@^4.1.2, graceful-fs@^4.1.6, graceful-fs@^4.1.9:
   version "4.1.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.1.11.tgz#0e8bdfe4d1ddb8854d64e04ea7c00e2a026e5658"
 
-"graceful-readlink@>= 1.0.0":
-  version "1.0.1"
-  resolved "https://registry.yarnpkg.com/graceful-readlink/-/graceful-readlink-1.0.1.tgz#4cafad76bc62f02fa039b2f94e9a3dd3a391a725"
-
 gray-matter@^3.0.8:
   version "3.1.1"
   resolved "https://registry.yarnpkg.com/gray-matter/-/gray-matter-3.1.1.tgz#101f80d9e69eeca6765cdce437705b18f40876ac"
@@ -4524,7 +4477,7 @@ handle-thing@^1.2.5:
   version "1.2.5"
   resolved "https://registry.yarnpkg.com/handle-thing/-/handle-thing-1.2.5.tgz#fd7aad726bf1a5fd16dfc29b2f7a6601d27139c4"
 
-handlebars@4.0.11:
+handlebars@4.0.11, handlebars@^4.0.3, handlebars@^4.0.5:
   version "4.0.11"
   resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.0.11.tgz#630a35dfe0294bc281edae6ffc5d329fc7982dcc"
   dependencies:
@@ -4534,16 +4487,6 @@ handlebars@4.0.11:
   optionalDependencies:
     uglify-js "^2.6"
 
-handlebars@^4.0.3, handlebars@^4.0.5:
-  version "4.0.10"
-  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.0.10.tgz#3d30c718b09a3d96f23ea4cc1f403c4d3ba9ff4f"
-  dependencies:
-    async "^1.4.0"
-    optimist "^0.6.1"
-    source-map "^0.4.4"
-  optionalDependencies:
-    uglify-js "^2.6"
-
 har-schema@^1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/har-schema/-/har-schema-1.0.5.tgz#d263135f43307c02c602afc8fe95970c0151369e"
@@ -4854,14 +4797,10 @@ iferr@^0.1.5:
   version "0.1.5"
   resolved "https://registry.yarnpkg.com/iferr/-/iferr-0.1.5.tgz#c60eed69e6d8fdb6b3104a1fcbca1c192dc5b501"
 
-ignore@^3.3.3:
+ignore@^3.3.3, ignore@^3.3.5:
   version "3.3.7"
   resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.7.tgz#612289bfb3c220e186a58118618d5be8c1bab021"
 
-ignore@^3.3.5:
-  version "3.3.8"
-  resolved "https://registry.yarnpkg.com/ignore/-/ignore-3.3.8.tgz#3f8e9c35d38708a3a7e0e9abb6c73e7ee7707b2b"
-
 import-local@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/import-local/-/import-local-1.0.0.tgz#5e4ffdc03f4fe6c009c6729beb29631c2f8227bc"
@@ -5405,11 +5344,7 @@ jquery@3.3.1, "jquery@^1.7 || ^2.0 || ^3.1":
   version "3.3.1"
   resolved "https://registry.yarnpkg.com/jquery/-/jquery-3.3.1.tgz#958ce29e81c9790f31be7792df5d4d95fc57fbca"
 
-js-base64@^2.1.8:
-  version "2.4.5"
-  resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.5.tgz#e293cd3c7c82f070d700fc7a1ca0a2e69f101f92"
-
-js-base64@^2.1.9:
+js-base64@^2.1.8, js-base64@^2.1.9:
   version "2.4.3"
   resolved "https://registry.yarnpkg.com/js-base64/-/js-base64-2.4.3.tgz#2e545ec2b0f2957f41356510205214e98fad6582"
 
@@ -5835,14 +5770,14 @@ lodash.uniq@^4.5.0:
   version "4.5.0"
   resolved "https://registry.yarnpkg.com/lodash.uniq/-/lodash.uniq-4.5.0.tgz#d0225373aeb652adc1bc82e4945339a842754773"
 
-lodash@^4.0.0, lodash@^4.17.10, lodash@~4.17.4:
-  version "4.17.10"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
-
-lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.2, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.3.0, lodash@^4.6.1:
+lodash@^4.0.0, lodash@^4.13.1, lodash@^4.14.0, lodash@^4.17.4, lodash@^4.17.5, lodash@^4.3.0, lodash@^4.6.1:
   version "4.17.5"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.5.tgz#99a92d65c0272debe8c96b6057bc8fbfa3bed511"
 
+lodash@^4.17.10, lodash@^4.17.2, lodash@~4.17.4:
+  version "4.17.10"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.10.tgz#1b7793cf7259ea38fb3661d4d38b3260af8ae4e7"
+
 log-symbols@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/log-symbols/-/log-symbols-1.0.2.tgz#376ff7b58ea3086a0f09facc74617eca501e1a18"
@@ -5899,20 +5834,13 @@ lowercase-keys@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/lowercase-keys/-/lowercase-keys-1.0.1.tgz#6f9e30b47084d971a7c820ff15a6c5167b74c26f"
 
-lru-cache@^4.0.1:
+lru-cache@^4.0.1, lru-cache@^4.1.1:
   version "4.1.3"
   resolved "https://registry.yarnpkg.com/lru-cache/-/lru-cache-4.1.3.tgz#a1175cf3496dfc8436c156c334b4955992bce69c"
   dependencies:
     pseudomap "^1.0.2"
     yallist "^2.1.2"
 
-lru-cache@^4.1.1:
-  version "4.1.2"
-  resolved "https://registry.yarnpkg.com/lru-cache/-/lru-cache-4.1.2.tgz#45234b2e6e2f2b33da125624c4664929a0224c3f"
-  dependencies:
-    pseudomap "^1.0.2"
-    yallist "^2.1.2"
-
 macaddress@^0.2.8:
   version "0.2.8"
   resolved "https://registry.yarnpkg.com/macaddress/-/macaddress-0.2.8.tgz#5904dc537c39ec6dbefeae902327135fa8511f12"
@@ -6307,14 +6235,10 @@ moment-timezone@0.5.17:
   dependencies:
     moment ">= 2.9.0"
 
-moment@2.22.1:
+moment@2.22.1, "moment@>= 2.9.0":
   version "2.22.1"
   resolved "https://registry.yarnpkg.com/moment/-/moment-2.22.1.tgz#529a2e9bf973f259c9643d237fda84de3a26e8ad"
 
-"moment@>= 2.9.0":
-  version "2.21.0"
-  resolved "https://registry.yarnpkg.com/moment/-/moment-2.21.0.tgz#2a114b51d2a6ec9e6d83cf803f838a878d8a023a"
-
 monotone-convex-hull-2d@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/monotone-convex-hull-2d/-/monotone-convex-hull-2d-1.0.1.tgz#47f5daeadf3c4afd37764baa1aa8787a40eee08c"
@@ -6723,11 +6647,7 @@ nwmatcher@1.3.6:
   version "1.3.6"
   resolved "https://registry.yarnpkg.com/nwmatcher/-/nwmatcher-1.3.6.tgz#db3bfdb01529af42c6c0162a0a38f6bf3300d3bd"
 
-"nwmatcher@>= 1.3.7 < 2.0.0":
-  version "1.4.3"
-  resolved "https://registry.yarnpkg.com/nwmatcher/-/nwmatcher-1.4.3.tgz#64348e3b3d80f035b40ac11563d278f8b72db89c"
-
-nwmatcher@^1.4.3:
+"nwmatcher@>= 1.3.7 < 2.0.0", nwmatcher@^1.4.3:
   version "1.4.4"
   resolved "https://registry.yarnpkg.com/nwmatcher/-/nwmatcher-1.4.4.tgz#2285631f34a95f0d0395cd900c96ed39b58f346e"
 
@@ -7926,37 +7846,7 @@ read-pkg@^3.0.0:
     normalize-package-data "^2.3.2"
     path-type "^3.0.0"
 
-"readable-stream@1 || 2", readable-stream@^2.0.0, readable-stream@^2.0.2, readable-stream@^2.0.4, readable-stream@^2.0.5, readable-stream@^2.1.4, readable-stream@^2.1.5, readable-stream@^2.2.2, readable-stream@^2.2.9, readable-stream@^2.3.3, readable-stream@^2.3.5, readable-stream@~2.3.3:
-  version "2.3.5"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.5.tgz#b4f85003a938cbb6ecbce2a124fb1012bd1a838d"
-  dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.3"
-    isarray "~1.0.0"
-    process-nextick-args "~2.0.0"
-    safe-buffer "~5.1.1"
-    string_decoder "~1.0.3"
-    util-deprecate "~1.0.1"
-
-readable-stream@1.1, readable-stream@^1.0.33, readable-stream@~1.1.9:
-  version "1.1.13"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.1.13.tgz#f6eef764f514c89e2b9e23146a75ba106756d23e"
-  dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.1"
-    isarray "0.0.1"
-    string_decoder "~0.10.x"
-
-"readable-stream@>=1.0.33-1 <1.1.0-0", readable-stream@~1.0.17, readable-stream@~1.0.27-1:
-  version "1.0.34"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.0.34.tgz#125820e34bc842d2f2aaafafe4c2916ee32c157c"
-  dependencies:
-    core-util-is "~1.0.0"
-    inherits "~2.0.1"
-    isarray "0.0.1"
-    string_decoder "~0.10.x"
-
-readable-stream@^2.0.1, readable-stream@^2.0.6:
+"readable-stream@1 || 2", readable-stream@^2.0.0, readable-stream@^2.0.1, readable-stream@^2.0.2, readable-stream@^2.0.4, readable-stream@^2.0.5, readable-stream@^2.0.6, readable-stream@^2.1.4, readable-stream@^2.1.5, readable-stream@^2.2.2, readable-stream@^2.2.9, readable-stream@^2.3.3, readable-stream@^2.3.5, readable-stream@~2.3.3:
   version "2.3.6"
   resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-2.3.6.tgz#b11c27d88b8ff1fbe070643cf94b0c79ae1b0aaf"
   dependencies:
@@ -7968,9 +7858,18 @@ readable-stream@^2.0.1, readable-stream@^2.0.6:
     string_decoder "~1.1.1"
     util-deprecate "~1.0.1"
 
-readable-stream@~1.1.0:
-  version "1.1.14"
-  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.1.14.tgz#7cf4c54ef648e3813084c636dd2079e166c081d9"
+readable-stream@1.1, readable-stream@^1.0.33, readable-stream@~1.1.0, readable-stream@~1.1.9:
+  version "1.1.13"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.1.13.tgz#f6eef764f514c89e2b9e23146a75ba106756d23e"
+  dependencies:
+    core-util-is "~1.0.0"
+    inherits "~2.0.1"
+    isarray "0.0.1"
+    string_decoder "~0.10.x"
+
+"readable-stream@>=1.0.33-1 <1.1.0-0", readable-stream@~1.0.17, readable-stream@~1.0.27-1:
+  version "1.0.34"
+  resolved "https://registry.yarnpkg.com/readable-stream/-/readable-stream-1.0.34.tgz#125820e34bc842d2f2aaafafe4c2916ee32c157c"
   dependencies:
     core-util-is "~1.0.0"
     inherits "~2.0.1"
@@ -8233,7 +8132,7 @@ request-promise-native@^1.0.5:
     stealthy-require "^1.1.0"
     tough-cookie ">=2.3.3"
 
-request@2, request@^2.81.0, request@^2.83.0:
+request@2, request@^2.55.0, request@^2.81.0, request@^2.83.0:
   version "2.86.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.86.0.tgz#2b9497f449b0a32654c081a5cf426bbfb5bf5b69"
   dependencies:
@@ -8286,7 +8185,7 @@ request@2.81.0:
     tunnel-agent "^0.6.0"
     uuid "^3.0.0"
 
-request@^2.55.0, request@~2.79.0:
+request@~2.79.0:
   version "2.79.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.79.0.tgz#4dfe5bf6be8b8cdc37fcf93e04b65577722710de"
   dependencies:
@@ -8536,14 +8435,10 @@ rxjs@^5.4.2, rxjs@^5.5.2:
   dependencies:
     symbol-observable "1.0.1"
 
-safe-buffer@5.1.1, safe-buffer@^5.0.1, safe-buffer@^5.1.0, safe-buffer@^5.1.1:
+safe-buffer@5.1.1, safe-buffer@^5.0.1, safe-buffer@^5.1.0, safe-buffer@^5.1.1, safe-buffer@~5.1.0, safe-buffer@~5.1.1:
   version "5.1.1"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.1.tgz#893312af69b2123def71f57889001671eeb2c853"
 
-safe-buffer@~5.1.0, safe-buffer@~5.1.1:
-  version "5.1.2"
-  resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
-
 safe-regex@^1.1.0:
   version "1.1.0"
   resolved "https://registry.yarnpkg.com/safe-regex/-/safe-regex-1.1.0.tgz#40a3669f3b077d1e943d44629e157dd48023bf2e"
@@ -8921,6 +8816,10 @@ sort-object@^0.3.2:
     sort-asc "^0.1.0"
     sort-desc "^0.1.1"
 
+sortablejs@^1.7.0:
+  version "1.7.0"
+  resolved "https://registry.yarnpkg.com/sortablejs/-/sortablejs-1.7.0.tgz#80a2b2370abd568e1cec8c271131ef30a904fa28"
+
 sorttable@1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/sorttable/-/sorttable-1.0.2.tgz#da67e34d32f6198bc12942b183b7a0f7c650f1a4"
@@ -8977,12 +8876,6 @@ source-map@^0.5.3, source-map@^0.5.6, source-map@^0.5.7, source-map@~0.5.1:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
 
-source-map@~0.2.0:
-  version "0.2.0"
-  resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.2.0.tgz#dab73fbcfc2ba819b4de03bd6f6eaa48164b3f9d"
-  dependencies:
-    amdefine ">=0.0.4"
-
 source-sans-pro@2.20.2:
   version "2.20.2"
   resolved "https://registry.yarnpkg.com/source-sans-pro/-/source-sans-pro-2.20.2.tgz#ee24a6f9680af4e05736be9c1afee3d714618782"
@@ -9062,11 +8955,7 @@ split@~0.2.10:
   dependencies:
     through "2"
 
-sprintf-js@^1.0.3:
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.1.1.tgz#36be78320afe5801f6cea3ee78b6e5aab940ea0c"
-
-sprintf-js@~1.0.2:
+sprintf-js@^1.0.3, sprintf-js@~1.0.2:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.0.3.tgz#04e6926f662895354f3dd015203633b857297e2c"
 
@@ -9237,14 +9126,10 @@ string.fromcodepoint@^0.2.1:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/string.fromcodepoint/-/string.fromcodepoint-0.2.1.tgz#8d978333c0bc92538f50f383e4888f3e5619d653"
 
-string.prototype.codepointat@0.2.1:
+string.prototype.codepointat@0.2.1, string.prototype.codepointat@^0.2.0:
   version "0.2.1"
   resolved "https://registry.yarnpkg.com/string.prototype.codepointat/-/string.prototype.codepointat-0.2.1.tgz#004ad44c8afc727527b108cd462b4d971cd469bc"
 
-string.prototype.codepointat@^0.2.0:
-  version "0.2.0"
-  resolved "https://registry.yarnpkg.com/string.prototype.codepointat/-/string.prototype.codepointat-0.2.0.tgz#6b26e9bd3afcaa7be3b4269b526de1b82000ac78"
-
 string.prototype.endswith@0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/string.prototype.endswith/-/string.prototype.endswith-0.2.0.tgz#a19c20dee51a98777e9a47e10f09be393b9bba75"
@@ -9261,7 +9146,7 @@ string.prototype.trim@~1.1.2:
     es-abstract "^1.5.0"
     function-bind "^1.0.2"
 
-string_decoder@^1.0.0, string_decoder@~1.0.3:
+string_decoder@^1.0.0:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.0.3.tgz#0fc67d7c141825de94282dd536bec6b9bce860ab"
   dependencies:
@@ -9782,14 +9667,10 @@ tsconfig@^6.0.0:
     strip-bom "^3.0.0"
     strip-json-comments "^2.0.0"
 
-tslib@^1.8.0:
+tslib@^1.8.0, tslib@^1.8.1:
   version "1.9.1"
   resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.9.1.tgz#a5d1f0532a49221c87755cfcc89ca37197242ba7"
 
-tslib@^1.8.1:
-  version "1.9.0"
-  resolved "https://registry.yarnpkg.com/tslib/-/tslib-1.9.0.tgz#e37a86fda8cbbaf23a057f473c9f4dc64e5fc2e8"
-
 tslint@5.10.0:
   version "5.10.0"
   resolved "https://registry.yarnpkg.com/tslint/-/tslint-5.10.0.tgz#11e26bccb88afa02dd0d9956cae3d4540b5f54c3"
@@ -9959,14 +9840,10 @@ unassertify@^2.0.0:
     through "^2.3.7"
     unassert "^1.3.1"
 
-underscore@1.9.0:
+underscore@1.9.0, underscore@^1.7.0:
   version "1.9.0"
   resolved "https://registry.yarnpkg.com/underscore/-/underscore-1.9.0.tgz#31dbb314cfcc88f169cd3692d9149d81a00a73e4"
 
-underscore@^1.7.0:
-  version "1.8.3"
-  resolved "https://registry.yarnpkg.com/underscore/-/underscore-1.8.3.tgz#4f3fb53b106e6097fcf9cb4109f2a5e9bdfa5022"
-
 underscore@~1.6.0:
   version "1.6.0"
   resolved "https://registry.yarnpkg.com/underscore/-/underscore-1.6.0.tgz#8b38b10cacdef63337b8b24e4ff86d45aea529a8"
diff --git a/zproject/settings.py b/zproject/settings.py
index 02ea509fd2..8697c9029b 100644
--- a/zproject/settings.py
+++ b/zproject/settings.py
@@ -913,6 +913,7 @@ JS_SPECS = {
             'node_modules/flatpickr/dist/flatpickr.js',
             'node_modules/flatpickr/dist/plugins/confirmDate/confirmDate.js',
             'node_modules/error-stack-parser/dist/error-stack-parser.min.js',
+            "node_modules/sortablejs/Sortable.js",
             'third/marked/lib/marked.js',
             'generated/emoji/emoji_codes.js',
             'generated/pygments_data.js',