Inset calculation bug in CardsViewController

[Alex293]

Hi,

If you run the demo on iOS 11 there is an inset on the collection view at the bottom of the size of the tabbar but not on iOS 10. I've looked at the code and in CardsViewController.viewDidLoad() constraint for the collection view are set not relatively to the safe area and with a tabbar height constant. So this cause the difference between iOS 11 and 10. This also cause a small difference at the top where on iOS 10 content is drawn below the status bar and not on iOS 11.