title: tap event does not fire on animated imageview
body: <p>I want an animating imageView with <code>UIBezierPath</code> (sliding from top to bottom) to be clicked. But every google help I found didn't solve it. But it does not print "clicked". </p>
  
  <p>The animation does work perfectly. Maybe anyone's got a clue? </p>
  
  <p>Help is very appreciated. </p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
  
      let imageView = UIImageView(image: UIImage(named: "advent_button"))
      let dimension = 25 + drand48() * 30
      imageView.frame = CGRect(x: 0, y: 0, width: dimension, height: dimension)
  
      let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(handleImageTap))
      imageView.addGestureRecognizer(tapGestureRecognizer)
      imageView.isUserInteractionEnabled = true
  
      let animation = CAKeyframeAnimation(keyPath: "position")
      animation.path = customPath().cgPath
      animation.duration = 20
      animation.fillMode = .forwards
      animation.isRemovedOnCompletion = false
      animation.repeatCount = 0.5
      animation.timingFunction = CAMediaTimingFunction(name: .easeOut)
  
      imageView.layer.add(animation, forKey: nil)
      view.addSubview(imageView)        
  }
  
  @objc func handleImageTap() {
      print ("clicked")
  }
  
  func customPath() -&gt; UIBezierPath {
      let path = UIBezierPath()
  
      path.move(to: CGPoint(x: 200, y: 0))
      let endpoint = CGPoint(x: 20 , y: 700)
      let cp1 = CGPoint(x: 90, y: 250)
      let cp2 = CGPoint(x: 180, y: 400)
      path.addCurve(to: endpoint, controlPoint1: cp1, controlPoint2: cp2)
      return path
  }
  </code></pre>