Move `npm install` to end of development installation process.

This should make it easier for users to recover from failed `npm
install` commands when setting up their environment.

README.dev.md

@@ -293,7 +293,6 @@ Finally continue with the All Systems instructions below.
 
 ```
 pip install -r requirements.txt
-npm install
 ./tools/install-phantomjs
 ./tools/download-zxcvbn
 ./tools/emoji_dump/build_emoji
@@ -304,6 +303,7 @@ if [ $(uname) = "OpenBSD" ]; then sudo cp ./puppet/zulip/files/postgresql/zulip_
 ./tools/do-destroy-rebuild-database
 ./tools/postgres-init-test-db
 ./tools/do-destroy-rebuild-test-database
+npm install
 ```
 
 To start the development server:

provision.py

@@ -155,8 +155,6 @@ def main():
     # project.
     os.chdir(ZULIP_PATH)
 
-    sh.npm.install(**LOUD)
-
     os.system("tools/download-zxcvbn")
     os.system("tools/emoji_dump/build_emoji")
     os.system("generate_secrets.py -d")
@@ -175,6 +173,9 @@ def main():
     sh.do_destroy_rebuild_database(**LOUD)
     sh.postgres_init_test_db(**LOUD)
     sh.do_destroy_rebuild_test_database(**LOUD)
+    # Run npm install last because it can be flaky, and that way one
+    # only needs to rerun `npm install` to fix the installation.
+    sh.npm.install(**LOUD)
     return 0
 
 if __name__ == "__main__":