title: Add a view on top of the keyboard using InputAccessoryView
body: <p>I'm trying to add a uiview to be on top of the keyboard always.
  I did it first with KeyboardWillShow/Hide, but it dosen't cover all
  cases and I'm trying to use inputAccesoryView.
  this is what I tried:</p>
  <pre><code>private var accessoryView = UIView(frame: CGRectZero)
  
  class ViewController : UIViewController {
  
      var myView: customUIView
  
      override var inputAccessoryView: UIView {
          return accessoryView
      }
  
      override func canBecomeFirstResponder() -&gt; Bool {
          return true
      }
  
      override func viewDidLoad() {
         super.viewDidLoad()
         accessoryView = myView
      }
  }
  </code></pre>
  <p>I get the following error :</p>
  <blockquote>
  <p>Terminating app due to uncaught exception
  'UIViewControllerHierarchyInconsistency', reason: 'child view
  controller:UICompatibilityInputViewController should have parent view
  controller:MyViewController but requested parent is:
  UIInputWindowController: '</p>
  </blockquote>
  <p>any help will be appreciated!</p>