title: MKAnnotation - Cannot assign to property: 'title' is a get-only property
body: <p>How do I resolve this build issue - I'm just trying to create an annotation for mapkit:</p>
  
  <p>ERROR: "MKAnnotation - Cannot assign to property: 'title' is a get-only property"</p>
  
  <pre><code>import UIKit
  import MapKit
  
  class ViewController: UIViewController {
  
      @IBOutlet weak var mapView: MKMapView!
  
      override func viewDidLoad() {
          super.viewDidLoad()
  
          // Annotations
          var annotation:MKAnnotation
          annotation.title = "test"    // ** ISSUE IS HERE **         
      }
  
      override func didReceiveMemoryWarning() {
          super.didReceiveMemoryWarning()
          // Dispose of any resources that can be recreated.
      }
  
  }
  </code></pre>
  
  <p>Notes:
   - Have downloaded latest version of XCode
   - is this to do with Swift 2.0?
   - </p>