BLD-1121: Create new group configurations page.
Merge pull request #4290 from edx/anton/create-new-configurations

Create new group configurations page.
auto-migrate old mongo to draft modulestore
Move modulestore django settings migration code down into the modulestore layer so it works for all django-based callers.
reverting back to migrating the settings in the env files
Added deprecation warnings.
Update opaque-keys library
Merge pull request #4380 from edx/nimisha/mongo-bwc-config

auto-migrate old mongo to draft modulestore
Add JQuery timepicker CSS to the unit and container templates
Merge pull request #4410 from edx/sarina/update-deprecation-warnings

Update opaque-keys library
Add "visible_to_staff_only" field to support staff locking in Studio.

STUD-1875
Implement close_connections and drop_database on modulestores.
Merge pull request #4402 from edx/christina/staff-lock

Add "visible_to_staff_only" field to support staff locking in Studio.
Change answer <-> response matching in capa.get_submission_metadata
Merge pull request #4370 from edx/nimisha/split-drop-database-2952

Implement close_connections and drop_database on modulestores.
Fix pending name changes template

- Strings marked for translation need to be wrapped in quotes to be
string type.
- Update old post function call
- Remove extra close brackets in function definitions
- Wrap href attribute in quotes
- Move square bracket outside of translated text
Merge pull request #4411 from edx/anton/group-experiments

Create new group configurations page
Add promise to ensure unit visibility is changed
Update (optional) Group Configuration urls to use settings.COURSE_KEY_PATTERN.
Merge pull request #4423 from edx/tim/group-conf-course-key-pattern

Update (optional) Group Configuration urls to use settings.COURSE_KEY_PATTERN