title: Swift Button.setText doesn't work with gradient
body: <p>I'm new in Swift and I have a problem. my button do not set the text if I try to use the gradient. here is my code: </p>
  
  <pre><code>let gradient:CAGradientLayer = CAGradientLayer()
      let colorBottom = UIColor(red: 9/255.0, green: 137/255.0, blue: 133/255.0, alpha: 1.0).CGColor
      let colorTop = UIColor(red: 222.0/255.0, green: 255.0/255.0, blue: 201.0/255.0, alpha: 1.0).CGColor
  
      gradient.colors = [colorTop, colorBottom]
      gradient.startPoint = CGPoint(x: 0.0, y: 0.5)
      gradient.endPoint = CGPoint(x: 1.0, y: 0.5)
      gradient.frame = LoginButton.bounds
      gradient.cornerRadius = 25.0
  
  
      LoginButton.layer.addSublayer(gradient)
      LoginButton.setTitle("Login", forState: UIControlState.Normal)
      LoginButton.setTitleColor(UIColor.blackColor(), forState: .Normal)
  
  
      self.view.addSubview(LoginButton)
  </code></pre>