CCX REST APIs
OAUTH2 authorization for CCX APIs
- oauth2 authorization required for ccx list.
- Course-instructor permission for ccx api endpoint
- Protection for detail view too.

Tests for CCX REST APIs and OAUTH2 authorization

CCX overrides course max_student_enrollments_allowed
and set it to 200 during CCX creation

Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar

Make the course URL pattern more generic.

Comment newly added functionality.

Fix quality issues.

Address two lint errors, with regex and variable naming.

Changed how we access course_key and course_id.

Replace another instance of self.course.id.to_deprecated_string()

Remove unused import, add missing one.

Improve how the ccx key is extracted from the URL

Use resolve() instead of os.path to get the course_id.

Remove the granting of staff access to coaches.

Also remove useless docstrings where they were added to keep pylint
quiet.

In the CCX dashboard, the Student Admin tab has a `Download student
grades` action. This action should download a CSV file containing
grades, but currently displays the CSV content in the browser instead.
This fix sets the `content-type` and `content-disposition` so that
a CSV file download occurs.

- fixes #93

If a block is marked as "hide from students" cannot be seen in the
CCX schedule

Make unpublish raise the same errors in split and old-mongo when asked to unpublish a DIRECT_ONLY_CATEGORY

TNL-3179

- Course overviews will cache courses upon publish.
- Added management command to warm up cache.
- OAuth2 handler returns courses via course overviews.

	modified:   lms/djangoapps/instructor/tests/test_enrollment.py

* Automatically create user partitions on course publish for each ICRV checkpoint.
* Disable partitions for ICRV checkpoints that have been deleted.
* Skip partitions that have been disabled when checking access.
* Add verification access control UI to visibility settings.
* Add verification access control UI to sequential and vertical settings.
* Add partition scheme for verification partition groups.
* Cache information used by verification partition scheme and invalidate the cache on update.
* Add location parameter to UserPartition so the partition scheme can find the associated checkpoint.
* Refactor GroupConfiguration to allow multiple user partitions.
* Add special messaging to ICRV for students in the honor track.

Authors: Zubair Arbi, Awais Qureshi, Aamir Khan, Will Daly

(cherry picked from commit 558b93fdeaaf72d02e050808698b2015e123a01c)

This reverts commit 42e78463.

This reverts commit 53db053c, reversing
changes made to 386a8a27.

This reverts commit d80e8364, reversing
changes made to fb5506a6.

enrollments.

The goal for this PR is to have a single mechanism for registering users and
reducing the number of places where special-casing for ccx courses is needed. The
migration at this point is purposefully limited to convert ccx memberships into
student enrollments when moving forward. No backward migration is in place at the
moment. The ccx membership tables are not removed at this time. It is possible to go
backwards and forwards multiple times with no errors or data loss.

This is a new TestCase base class, intended for situations where
you only want to initialize course content in the setUpClass(),
as opposed to setUp(). This is done for performance reasons, since
many test cases only use courses in a read-only fashion,
particularly in LMS tests.

This commit also converts the following modules to use this new
base class:

  lms/djangoapps/ccx/tests/test_ccx_modulestore.py (38s -> 4s)
  lms/djangoapps/discussion_api/tests/test_api.py (2m45s -> 51s)
  lms/djangoapps/teams/tests/test_views.py (1m17s -> 33s)