requirements: Add premailer for inlining email CSS.

requirements/common.txt

@@ -79,6 +79,9 @@ html2text==2016.9.19
 httplib2==0.10.3
 -e git+https://github.com/umairwaheed/talon.git@7d8bdc4dbcfcc5a73298747293b99fe53da55315#egg=talon==1.2.11
 
+# Needed for inlining the CSS in emails
+premailer==3.1.1
+
 # Needed for JWT-based auth
 PyJWT==1.5.2
 

requirements/dev_lock.txt

@@ -39,7 +39,8 @@ constantly==15.1.0        # via twisted
 cookies==2.2.1            # via moto
 coverage==4.4.1
 cryptography==2.0.3
-cssselect==1.0.1          # via parsel, scrapy
+cssselect==1.0.1          # via parsel, premailer, scrapy
+cssutils==1.0.2           # via premailer
 decorator==4.1.2          # via ipython, traitlets
 defusedxml==0.5.0
 dicttoxml==1.7.4          # via moto
@@ -73,7 +74,7 @@ ipython==6.1.0
 jedi==0.10.2              # via ipython
 jinja2==2.9.6
 jmespath==0.9.3           # via boto3, botocore
-lxml==3.8.0               # via parsel, scrapy
+lxml==3.8.0               # via parsel, premailer, scrapy
 markdown-include==0.5.1
 markdown==2.6.9           # via markdown-include
 markupsafe==1.0
@@ -93,6 +94,7 @@ pika==0.10.0
 pillow==4.2.1
 pip-tools==1.9.0
 polib==1.0.8
+premailer==3.1.1
 prompt-toolkit==1.0.15    # via ipython
 psycopg2==2.7.3
 ptyprocess==0.5.2         # via pexpect

requirements/prod_lock.txt

@@ -25,7 +25,8 @@ certifi==2017.7.27.1
 cffi==1.10.0
 chardet==3.0.4
 cryptography==2.0.3
-cssselect==1.0.1
+cssselect==1.0.1          # via premailer
+cssutils==1.0.2           # via premailer
 decorator==4.1.2          # via ipython, traitlets
 defusedxml==0.5.0
 diff-match-patch==20121119
@@ -51,7 +52,7 @@ ipython-genutils==0.2.0   # via traitlets
 ipython==6.1.0
 jedi==0.10.2              # via ipython
 jinja2==2.9.6
-lxml==3.8.0
+lxml==3.8.0               # via premailer
 markdown-include==0.5.1
 markdown==2.6.9           # via markdown-include
 markupsafe==1.0
@@ -67,6 +68,7 @@ pickleshare==0.7.4        # via ipython
 pika==0.10.0
 pillow==4.2.1
 polib==1.0.8
+premailer==3.1.1
 prompt-toolkit==1.0.15    # via ipython
 psycopg2==2.7.3
 ptyprocess==0.5.2         # via pexpect

version.py

@@ -1,2 +1,2 @@
 ZULIP_VERSION = "1.6.0+git"
-PROVISION_VERSION = '9.10'
+PROVISION_VERSION = '9.11'