title: Update value using the direct path instead of "an object"
body: <p>is it possible to update a direct path in firebase instead of the object of the path?</p>
  
  <p>for example, instead of this: (which works)</p>
  
  <pre><code>newsRef = db.ref("/news")
  newsRef.update({
              image: imageURL
            });
  </code></pre>
  
  <p>do something like this? (which does not work)</p>
  
  <pre><code>newsRef = db.ref("/news/image")
      newsRef.update(imageURL)
  </code></pre>