Estute/xenial and browser updates for testing

(cherry picked from commit 26b05673)

Fix lettuce tests for Xenial compatibility and newer Chrome version.

(cherry-picked from c3887b0b)

Properly wait for LTI stub's buttons to render

(cherry-picked from c58e5142)

Workaround for intermittent chromedriver hangs upon start.

(cherry-picked from 840efb23)

Refactor click since it was resulting in timeout errors; use correct id for one of the LTI stub's buttons.

(cherry-picked from 452a1f1f)

Solve open sans quotation issue with tests.

(cherry-picked from 0e7e9468)

Fixes for chrome reliability in selenium.

Fix for rendering timing issue. See https://bugs.chromium.org/p/chromedriver/issues/detail?id=1552

(cherry-picked from e7b0c28d)

Multi-thread stub servers.

(cherry-picked from 0e596dd5)

Lettuce-on-Xenial CMS fix. Iterate through a list to avoid quotation string confusion.

Also change some selenium settings (they were not necessary at this time).

(cherry-picked from c0dd2b87)

TNL-6553

(cherry-picked from f1655051)

(cherry-picked from cb7e260c)

(cherry-picked from 2014f450)

(cherry-picked from 292b425c)

(cherry-picked from 3b7ab3f0)

(cherry-picked from c0dd2b87)

(cherry picked from commit 20447f28)

Label the Platform API book for Ficus

Cherry-pick the email uniqueness constraint onto Ficus

Added unique constraint on email
ECOM-7085

(cherry picked from commit d141eb15)

No-op a migration that needs to be more clever

(cherry picked from commit 1e6a74e7)

model_name can be non-None, and model is still None

(cherry picked from commit 52ca02fd)

An idempotent migration to add an email uniqueness constraint

(cherry picked from commit 169414b7)

Make this no-op migration be a true no-op.

(cherry picked from commit 04557bbf)

A new django app for unicorn migrations

(cherry picked from commit 98b250b6)

Remove migration deleting XBlockDisableConfig model to allow zero-downtime release upgrades.

(cherry picked from commit d73d2f58)

Cherry picked from eb3367e6

Cherry pick from 16f8f960

Cherry pick from deb69de6

and a comment and explaining why we import aws.* in the openstack settings.

(cherry picked from commit 9d5db5ae)

(cherry picked from commit 46797666)

* Allows temporary URLs to work from Private SWIFT storage, e.g. for grade report downloads.

(cherry picked from commit 32f9532d)

Fix two wrong egg names

These are the only two egg names that are wrong in this file.  We have
to uninstall i18n-tools, because the distribution name changed.  The
lti-consumer XBlock hasn't changed named, we just had the wrong name in
the requirements file.

(cherry picked from commit 91a235a9)

Add versions to all non-dash-e installations

(cherry picked from commit a117416e)

Try the latest of pip and setuptools

(cherry picked from commit 041fede3)

Use latest pyparsing 2.0.x to avoid setuptools entanglement

With 2.0.1, and setuptools 34.0.2, errors happen like:

File "/edx/app/edxapp/venvs/edxapp-sandbox/local/lib/python2.7/site-packages/packaging/requirements.py", line 59, in <module>
    MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
TypeError: __call__() takes exactly 2 arguments (1 given)

(cherry picked from commit 73519b35)
(cherry picked from commit 8d791b58)

Keep the sandbox reqs in sync

(cherry picked from commit 84b25dd8)

Pyparsing might need to be in pre?

(cherry picked from commit 4433edd0)

edx-i18n-tools is on PyPI, get it from there.

(cherry picked from commit 7f4ce79c)

With 2.0.1, and setuptools 34.0.2, errors happen like:

File "/edx/app/edxapp/venvs/edxapp-sandbox/local/lib/python2.7/site-packages/packaging/requirements.py", line 59, in <module>
    MARKER_EXPR = originalTextFor(MARKER_EXPR())("marker")
TypeError: __call__() takes exactly 2 arguments (1 given)

Cale/rc merge branch

Retry on all exceptions on failed subsection grade update

Merge Release into Master

This access pattern was wrong, and was causing errors in production. I've
included an additional happy-path test.

Happy New Year

Merge Release candidate into Release

Change CourseTeamMembership emit to use proper id