title: UIRefreshControl added to UIScrollView is never shown
body: <p>I have decided to use UIScrollView instead of UITableView in my app for many reasons. When I was using UITableView, I was able to add a UIRefreshControl with no issue whatsoever. When I use the same code on my UIScrollView however, nothing happens. I have tried several third-party refresher libraries, and none seem to work. Any help is appreciated.</p>
  
  <p>Source:</p>
  
  <pre><code>var scroll: UIScrollView!
  var refreshControl: UIRefreshControl!
  
  override func viewDidLoad()
  {
      super.viewDidLoad()
  
      self.scroll = UIScrollView(frame: self.view.frame)
      self.scroll.contentSize = CGSize(width: self.view.bounds.width, height: 10)
  
      self.refreshControl = UIRefreshControl()
      self.refreshControl.attributedTitle = NSAttributedString(string: "Pull to refresh")
      //self.refreshControl.addTarget(self, action: "loadPostsIntoCards", forControlEvents: UIControlEvents.ValueChanged)
      self.scroll.addSubview(self.refreshControl)
  
      self.view.addSubview(self.scroll)
  
      //self.loadPostsIntoCards()
  }
  </code></pre>
  
  <p>The <code>loadPostsIntoCards</code> method does my API call, and creates UIViews ("cards") that are added to the UIScrollView. I then change the contentSize of the UIScrollView based upon the total height of all the cards. The cards are added perfectly, and the scroll view acts as expected, except with regards to the UIRefreshControl.</p>
  
  <p>Thanks in advance for any help!</p>