title: UIRotationGestureRecognizer activates multiple times Swift
body: <p>When using <code>UIRotationGestureRecognizer</code> the rotation is recognized but it triggers the action multiple times. Here is my code:</p>
  
  <pre><code>override func viewDidLoad() {
      super.viewDidLoad()
      // Do any additional setup after loading the view, typically from a nib.
      let rotation = UIRotationGestureRecognizer(target: self, action: #selector(ViewController.lol))
      self.view.addGestureRecognizer(rotation)
  }
  
  func lol() {
      print ("hi")
      UIView.animateWithDuration(5.0, animations: {
          let currTransform = self.view.transform
          let newTransform = CGAffineTransformConcat(currTransform, CGAffineTransformMakeRotation(CGFloat(M_PI)))
          self.view.transform = newTransform
  
      })
  }
  </code></pre>