How do I sign out users in Firebase 3.0?
<p>According to <a href="https://firebase.google.com/docs/reference/js/firebase.auth.Auth" rel="noreferrer">documentation</a>, I force a user to sign out with the method <code>signOut()</code>.</p>

<p>This is what I have tried:</p>

<pre><code>var rootRef = firebase.database().ref();
var loggedInUser = firebase.auth();

1. firebase.signOut(); 
2. loggedInUser.signOut(); 
3. rootRef.signOut();
4. signOut();
5. firebase.auth.signOut();
</code></pre>

<p>I get <code>... is not a function</code> for every one of the five above. I know there is no issue with my reference to the new Firebase, since <code>firebase.database().ref();</code> and <code>firebase.auth();</code> does not throw error. I have also migrated the app in the console.</p>