New Test Class PlayOnceTest

##Rationale
* New test class "PlayOnceTest" created in order to test the order of events while the

##Changed Files
* Created new class PlayOnceTest, which will test to see if the Sample App's timeline is working correctly a PLAY event is emitted by tests.
* setUp method set to listen for and Log all Play, didPlay, and adDataReady events, as well as add them to the list actualEventList.
* New utility method timelineLoop checks the order of the events by comparing a preset array to the order of events.
* New test method testTimeline created to call upon timelineLoop.
Made suggested changes
Merge pull request #49 from BrightcoveOS/onceux-play-once-test

New OnceUx Test Class PlayOnceTest