title: how to Scroll(horizontally) in collection view on button press?
body: <p>I have a collection view with images.I want to perform scrolling on button press . i have searched on google I found out only to set contentoffset but I want to scroll with animations(scroll should bounce if content is past the scrolling area).I have added a <a href="http://i.stack.imgur.com/RtiCf.png" rel="nofollow">image</a> to show you what exactly i have to do, in picture there is a collection view and little arrows on both sides are buttons.</p>
  
  <pre><code> @IBAction func moveScrollLeft(sender: UIButton) {
      UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
          self.imageCollectionView.contentOffset.x -= 50
          }, completion: nil)
      print(imageCollectionView.contentOffset.x)
  }
  
  @IBAction func moveScrollRight(sender: UIButton) {
      UIView.animateWithDuration(0.2, delay: 0, options: UIViewAnimationOptions.CurveEaseOut, animations: {
          self.imageCollectionView.contentOffset.x += 50
          }, completion: nil)
      print(imageCollectionView.contentOffset.x)
  
  }
  </code></pre>