The ASHSpringyCollectionView can't scroll sometimes

[menglexiang]

I use the ASHSpringyCollectionView in my project. It works prefect.but It has a bed bug:when the content height less than screen height,the ASHSpringyCollectionView can't scroll!hope you can solve it,thanks~

[menglexiang]

add a single line of code.
self.collectionView.alwaysBounceVertical = YES;