title: firebase.database.ServerValue.TIMESTAMP return an Object
body: <p>I'm working on a web project with Firebase.
  I call:</p>
  
  <pre><code>firebase.database.ServerValue.TIMESTAMP
  </code></pre>
  
  <p>and it returns:</p>
  
  <pre><code>{.sv: "timestamp"}
  </code></pre>
  
  <p>How will I get time of Firebase server with javascript?</p>