Credit requirement optimizations

Credit eligibility/provider refactor

* Skip adding the credit req tasks to the queue for non-credit courses.
* Load only ICRV XBlocks instead of traversing the course tree.

mattdrayer/SOL-1018: Fixed progress template for better web certificates support

Fix XBlock class loading in local resource view

Merge back into master

* Remove m2m relation between credit course and credit providers.
* Separate eligibility and provider APIs into different modules.
* Add API call for retrieving a user's eligibilities.
* Cache credit course list.
* Style the dashboard purchase button.
* Display a link for the credit provider on the dashboard.
* Add analytics events for clicks on the purchase button.
* Expose more credit models to Django admin and add search functionality.

use 1 coveragerc file to generate 1 coverage report per build

Mark test as flaky; TNL-2647

InstrDash and Wiki content responsive

Support running Studio with optimized assets

Lower pylint threshold to 7000!

Make edxmako cache properly with changing lookup paths

Revert "Fixed randomized problems which were not appearing to work."

Add the Poll XBlock to the requirements.

Fix errors with fetching Shibboleth metadata

Make resetting of attempts and student state on blocks recursive. (SOL-858)

Team card/listing

Fixed randomized problems which were not appearing to work.

Fix not being able to set course passing grades above 80%.

TNL-2551

Order of Credit Eligibility line items

Displayed eligibility line items on the Progress page of a Credit course
in the order of appearance in the courseware.

ECOM-1782

Added Courses endpoint for Commerce API

XCOM-314

Improve logging of ecommerce interactions

Dark lang middleware: Check if user is authenticated

Check if the request's user is authenticated before attempting to
get their user preferences. Otherwise, log warnings appear indicating
the UserNotFound error was caught.

TNL-2623 Fix bug where status icons were hidden in image response problems

give the header the right height in the verify flow