title: remove specific class from html string using php
body: <p>I have a string like </p>
  
  <pre><code>$string = '&lt;img class="img-responsive animate scale animated" src="image/catalog/blocks/about-banner.jpg" alt=""&gt;';
  </code></pre>
  
  <p>I want to remove <code>img-responsive</code> class from it. How?</p>