iCarousel's implementation of -layoutSubviews needs to call super

When adding an iCarousel in interface builder, then adding other views to the view that each of auto layout constraints, I get this error:

    Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Auto Layout still required after executing -layoutSubviews. iCarousel's implementation of -layoutSubviews needs to call super.'

Doing what the exception tells us to do, fixes the problem.