Check for status in test.
Add test for track url.
Fix test to use cookie.
Use download_track in feature file.
Add new tests for get_transcript.
Add html5 test.
Add content check.
Add tests for available_translations dispatch.
Disable flaky cms test.
Add w/o english transcript tests.
Add to changelog.
Refactored stub services for style and DRY
Added unit tests for stub implementations
Updated acceptance tests that depend on stubs.
Updated Studio acceptance tests to use YouTube stub server; fixed failing tests in devstack.