Merge pull request #304 from avalonmediasystem/master

Merge 3.0.0 back into develop
Remove release tags from Gemfile
Renaming mispelled permalink filename

While working on extracting the permalink behavior from Avalon,
we encountered a misnamed file.
Merge pull request #306 from jeremyf/renaming-permalink-spec-file

Renaming mispelled permalink filename
Merge pull request #308 from avalonmediasystem/hotfix/matterhorn-security-issue

Update submodule with fix for matterhorn LTI/OAuth vulnerability
Merge pull request #309 from avalonmediasystem/hotfix/matterhorn-security-issue

update avalon-felix submodule
Bumped rake version to avoid error
Extract poster/thumbnail via HLS if master file is not present
Fall back to -i -ss if -ss -i doesn't work
Merge pull request #312 from avalonmediasystem/feature/extract-via-hls

Extract poster/thumbnail from streaming server via HLS if master file is not present
Tests for m3u8_reader.rb
VOV-2660 Implement interface and persistence for pre-existing permalinks
Merge pull request #311 from avalonmediasystem/feature/VOV-2660

Feature/vov 2660
Remove unused admin controller
fix truncate center and add tests
Fix function name typo in migration
Update search_result_label tests
add test for milliseconds_to_formatted_time
Add tests to models/concerns/visibility
Testing