Update messaging to mention MicroMasters

TNL-6113

Update version number.

Increment banner polling from 30 seconds to 60 seconds.

Fix icon alignment for practice exams

Release 0.16.0

Allow authors to remove option for unproctored exams

TNL-5084

Update version number to 0.15.0.

Delete in-client polling.

Also remove app shutdown logic.

Check and Final Check are being replaced in Capa with Submit.

Release 0.14.0

Introduce id verification step for proctored exams

TNL-5083

Create a mock backend that bypasses proctoring step.

Clean up the Python tests

French i18n

Add an OEP-2 compliant openedx.yaml file

Don't error out if the credit service returns None.

Update version number for proctoring release candidate.