Add a check for beta users in the video_info API

Discovered a case I missed on the original version of this. See
https://github.com/edx/edx-platform/pull/5798
JIRA: MA-76

Also fixes checking for mobile_access when course is None
JIRA: MOB-978
MA-141 Support webm encoding for VAL-enabled videos
Updated open sans webfonts with latest.
TNL-395
Merge pull request #5945 from edx/waheed/tnl395-updated-open-sans-webfonts

Updated open sans webfonts with latest.
Merge pull request #5920 from edx/aleffert/additional-beta-checks

Add a check for beta users in the video_info API
Merge pull request #5981 from edx/mobile/MA-141

MA-141 Support webm encoding for VAL-enabled videos
Remove ability to add new ORA 1 problems to courses
TNL-827