title: Cloudinary: cloudinary_url() method fallback
body: <p>Is there a fallback option when using <code>cloudinary_url()</code> if Cloudinary is unavailable (such as when working in dev offline)?</p>
  
  <p>In this particular case, I've uploaded my static assets to Cloudinary and am using <code>cloudinary_url</code> in my css to pull in the background image. e.g.:</p>
  
  <pre><code>background-image: cloudinary_url("background.jpg");
  </code></pre>
  
  <p>However if Cloudinary is unavailable, I would like this to fallback to <code>/assets/images/background.jpg</code></p>