Add track_enrollment model
Annotate track enrollment model
Add enroll endpoint for tracks
Add methods to check if a user is enrolled in a track
Account for when the user is nil for telling if they are enrolled
Add track associations to users
Make partial for showing a track. Add an enroll view that just shows a track for now (will show a modal)
Add associations for users and tracks via track_enrollments
Add ability to see the enroll page for everyone (including not signed in)
Add custom pluralize method for strings
Allow users to enroll in tracks
Merge pull request #1329 from teamleada/mark-track-enrollment

Track enrollment