Migrate to Swift 4.2 and add settings for iPhone X, Xs, XR and Xs Max…

… landscape support

bug fix on removeAllItems

release 1.5

Introduce new properties to allow set number of items per screen for
multiple screen sizes instead of setting minimum margins, as well as
new properties to center subviews when items are not wide enough to use
whole screen width

another one...

Add support to nib

Add support to nib, just change the class on nib file to
ASHorizontalScrollView

Adapt Swift 3 and fix bug

Change C style code to swift 3 format, fix removeItemAtIndex last index
crash bug

Adapt iOS SDK 9.0

Add comments on functions, remove scale when calculating margin, it
seems that the behaviour in iOS 9 change the way of align views

Update pod