Show course home messages for important course dates

LEARNER-2073

LEARNER-2546 Take users from track selection to course home instead of dashboard 

Bump problem-builder requirement to 2.7.7.

Fix saving of common/lib xunit test results.

Bump enterprise to 0.48.2

Use django file storage URLs for all course export downloads.

Upgrade django-pyfs to 1.0.7

LEARNER-2546

increase staff user rate limit

Update raw sql that uses datetimes to be Django 1.9 compatible

Paver changes to run tox testing for system & lib tests.

Remove fb-sdk from base.txt requirements

Add 'Hours of Effort' to Spanish certificates template context

Grades: remove read_only param and create method

fixup! Enable tox testing of system and commonlib via paver. Add support for django_version option to support Django 1.8/1.11.

Add support for django_version option to support Django 1.8/1.11.

update edx-proctoring to 1.2.2

EDUCATOR-139 add log to identify the cause of error

Update Translations

We now iterate over the given team members and create them individually, rather than in bulk. This avoids uniqueness errors that arise when we attempt a bulk create operation with an existing row.

LEARNER-2468

Facebook wants from edX to upgrade all graphAPI calls to v2.9,
after investigation it can be seen that edX-platform is accessing
graphAPI through python-social-auth package that is already accessing
v2.9.'base.txt' of the requirements has fb-sdk package that is also used
to access graphAPI,but currently, there is no area in our code that is
using this library that's why there is no need of it in requirements.

LEARNER-2620

EDUCATOR-171

ENT-656: Create API View for ApiAccessRequest model

Ent 624 update enterprise api support