Add a test for compositeView behaviors

Fixes #1389 
~~Shows the error in #1389~~

~~This seems to be a problem with the event not getting set in the childView.~~

~~as @MasterLambaster said~~


~~>  i guess it's caused by fd74e60. CollectionView uses buffering and does not use regions, therefore onShow is not triggered for Behavior. It works just fine on 1.8.5~~

~~Well i just stripped down the tests and they are no longer failing... need to think about why~~