Retain cycle in animator. Need to set completion properties to nil after animation.

[EugeneEl]

Hi!
I was looking for already-made solution for custom transition. But when I checking your example for zoom transition https://github.com/xxxAIRINxxx/ARNZoomImageTransition
I noticed that deinit for detail controller never been called. After investigation I found that problem is in ARNTransitionAnimator.

public func animationEnded(transitionCompleted: Bool) {
        self.transitionContext = nil

        // also need to set completions to nil 
        self.presentationBeforeHandler = nil
        self.presentationAnimationHandler = nil
        self.presentationCancelAnimationHandler = nil
        self.presentationCompletionHandler = nil
        self.dismissalBeforeHandler = nil
        self.dismissalAnimationHandler = nil
        self.dismissalCancelAnimationHandler = nil
        self.dismissalCompletionHandler = nil
}

To be honest I didn't dive into iOS transition API deep enough to be sure where capturing occurs but I found this solution might help.

Please fix this as retain cycles cause crashes hard to detect.

[xxxAIRINxxx]

@EugeneGoloboyar
Thanks for the issue.
I working on creating a Swift 3 version.
Code varies greatly, but the problem is going to improve.

I'm so busy now...
please wait for a while..

[nfhipona]

ohhh.. cool then I think we'll just wait for your changes.