title: Swift 3.0 unresolved identifier for DispatchQueue
body: <p>I have been trying to find the answer to this for hours now but still no avail. I am trying to use the following code:</p>
  
  <pre><code>func fetchPosts() {
      ref.child("Amore").child("Posts").observeSingleEventOfType(.Value, withBlock: { (snapshot) in
          if let dictionary = snapshot.value as? [String: AnyObject] {
              let postMod = ReviewsPostModel()
  
              postMod.setValuesForKeysWithDictionary(dictionary)
              self.posts.insert(postMod, atIndex: 0)
          }
  
          DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
              self.tableView.reloadData()
          }
      })
  }
  </code></pre>
  
  <p>In Swift 3.0.1, but it is saying that "DispatchQueue" is an unresolved identifier. I have imported Dispatch, and made sure that the class was pointed at the right target file. Any and all help is greatly appreciated.</p>