title: hide element for medium and up devices bootstrap
body: <p>I am trying to hide an element for medium devices and upwards. According to the <a href="http://v4-alpha.getbootstrap.com/layout/responsive-utilities/" rel="nofollow">bootstrap docs</a> i just need to add the class <code>hidden-md-up</code> to the element in question. This ism't working though.</p>
  
  <p>Please see demo below. I have added the class <code>hidden-xs-up</code> even though i need <code>hidden-md-up</code> because it's easier to test within the jsfiddle viewport.</p>
  
  <p>DEMO <a href="https://jsfiddle.net/DTcHh/21979/" rel="nofollow">https://jsfiddle.net/DTcHh/21979/</a></p>
  
  <pre><code>&lt;img src="http://placehold.it/350x150" class="hidden-md-up" /&gt;
  </code></pre>