Update canvas_user_activities.rb

when there is no source for activity, the source should default to bCourses instead of Canvas
Update canvas_user_activities_spec.rb

CLC-2473 - when there is no emitter, source should revert to bCourses instead of Canvas
Merge pull request #1615 from jonmhays/master

CLC-2473 - Update canvas_user_activities.rb
[CLC-2590] Telebears -> Tele-BEARS
[CLC-2598] Tele-BEARS needs to be feature flagged
Merge pull request #1617 from yuhunglin/CLC-2590

[CLC-2590] [CLC-2598] Typo fix and feature flag for telebears
CLC-2511 Initial Canvas course provisioning for admins
Full admin workflow is supported.
No CSS; no display of existing sites; lots of missing text.