title: It keeps telling me "Class 'GameScene' has no initializers"
body: <pre><code>import SpriteKit
  
  class GameScene: SKScene {
      var movingGround: JTMovingGround!
      var hero: JTHero
  
      override func didMoveToView(view: SKView) {
         backgroundColor = UIColor(red: 159.0/255.0, green: 281.0/255.0, blue: 244.0/255.0, alpha: 1.0)
         movingGround = JTMovingGround(size: CGSizeMake(view.frame.width, 20))
          movingGround.position = CGPointMake(0, view.frame.size.height/2)
          addChild(movingGround)
  
          hero = JTHero()
          hero.position = CGPointMake(70, movingGround.position.y + movingGround.frame.size.height/2 + hero.frame.height/2)
          addChild(hero)
      }
  
      override func touchesBegan(touches: Set&lt;NSObject&gt;, withEvent event: UIEvent) {
          movingGround.start()
      }
  
      override func update(currentTime: CFTimeInterval) {
          /* Called before each frame is rendered */
      }
  }
  </code></pre>
  
  <p>could someone tell me what went wrong?? thanks</p>