title: Type 'Any' has no subscript members after updating to Swift 3
body: <p>Here is my code in Swift:</p>
  
  <pre><code>currentUserFirebaseReference.observeSingleEvent(of: .value, with: { (snapshot: FIRDataSnapshot) in
          let UID = snapshot.key
          let pictureURL = snapshot.value!["pictureURL"] as! String
          let name = snapshot.value!["displayname"] as! String
          let currentUser = Person(name: name, bio: "", UID: UID, pictureURL: pictureURL)
          self.currentUserInfo = currentUser
              })
  </code></pre>
  
  <p>I just updated to Xcode 8 / Swift 3, which seems to have caused the following error message:</p>
  
  <blockquote>
    <p>"Type 'Any' has no subscript members"</p>
  </blockquote>
  
  <p>I call <code>snapshot.value!["</code>insert something here<code>"]</code> in many places in my code, I'm getting this error and I can't run my code.</p>
  
  <p>The following code works:   </p>
  
  <pre><code>let pic = (snapshot.value as? NSDictionary)?["pictureURL"] as? String ?? ""
  </code></pre>
  
  <p>However, I don't see what changed or what makes this necessary now versus how it was before.</p>
  
  <p>The only thing that has changed as far as I'm aware is the syntax of the observe, but I don't understand why this caused my code to stop working.</p>