Fix: initialize "attempts" to 0 to ensure proper counting of attempts.
Moves rendering of ExercisePractice and Playlist Views until after statusModel is loaded.
Prevents race conditions in rendering.
modify number of repeats for each test
Introduces tests for student_testing.
Merge pull request #2214 from rtibbles/exercise_race_condition

Fix race condition in Exercise Practice
Merge pull request #2221 from learningequality/nalanda-rct2

Release Nalanda RCT2 updates