title: Property 'map' does not exist on type 'FirebaseListObservable<any[]>'
body: <p>Just bumped my angularfire2 and firebase and now getting:</p>
  
  <p><code>Property 'map' does not exist on type 'FirebaseListObservable&lt;any[]&gt;'</code></p>
  
  <p>Tried importing <code>import "rxjs/add/operator/map";</code></p>
  
  <p>But does not work.</p>
  
  <p>What is further confusing, is that map exists: <a href="https://angularfire2.com/api/classes/_utils_firebase_list_observable_.firebaselistobservable.html" rel="nofollow noreferrer">https://angularfire2.com/api/classes/_utils_firebase_list_observable_.firebaselistobservable.html</a> </p>
  
  <p>Version:
  <code>"angularfire2": "^2.0.0-beta.7-pre",
  "firebase": "^3.6.8"</code></p>
  
  <p>(this is also an ionic 2 app, though not sure that is relevant)
  How do I go about post processing a FirebaseListObservable?</p>