title: Firebase ref.on("value" is getting called even without a change in value - node.js
body: <p>I am trying to observe a change in my firebase DB.</p>
  
  <p>This is my structure</p>
  
  <p>DB
   - Authenticate : true </p>
  
  <p>I am listening to changes in Authenticate like this in my node.js app</p>
  
  <pre><code>var authRef = firebase.database().ref('Authentication');
        authRef.on('value', function(snapshot) {
                console.log(snapshot.val());
                res.send(snapshot.val());
        });
  </code></pre>
  
  <p>But as soon as I call <code>authRef.on</code> , it is fetching the previous value instead of waiting for a change.</p>
  
  <p>Please advice.</p>