title: UIImageView UITapGestureRecognizer not working
body: <p>Tap gesture event not gettint called. I may be doing something wrong, but please have a look (I tried adding recognizer to self.view but still no luck) : </p>
  
  <p><strong>LoginViewController</strong></p>
  
  <pre><code>class LoginViewController: UIViewController {
  
      override func viewDidLoad() {
          super.viewDidLoad()
  
          let container = UIView() 
  
          container.heightAnchor.constraintEqualToConstant(50).active = true
  
          let myVC1 = MyViewController()
          let myVC2 = MyViewController()
          let myVC3 = MyViewController()
          let myVC4 = MyViewController()
  
          let myStackView = UIStackView(arrangedSubviews: [myVC1.view, myVC2.view, myVC3.view, myVC4.view])
          myStackView.spacing = 10
          myStackView.alignment = .Fill
          myStackView.distribution = .EqualSpacing
  
          container.addSubview(myStackView)
          view.addSubview(container)
      }
  }
  </code></pre>
  
  <p><strong>MyViewController</strong></p>
  
  <pre><code>class MyViewController: UIViewController, UIGestureRecognizerDelegate {
  
      let ImageView = UIImageView()
  
      override func viewDidLoad() {
          super.viewDidLoad()
          ImageView.backgroundColor = UIColor.blueColor()
          let tapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(pressedSocialMediaItem(_:)))
          tapGestureRecognizer.delegate = self
          tapGestureRecognizer.numberOfTapsRequired = 1
  
          ImageView.userInteractionEnabled = true
          ImageView.addGestureRecognizer(tapGestureRecognizer)
  
          view.addSubview(ImageView)
      }
  
      func pressedSocialMediaItem(sender : UITapGestureRecognizer) { 
          print("PRESSED ! ")
      }
  }    
  </code></pre>