title: Adding panel-heading:hover class in bootstrap less does not change the hover color
body: <p>I have added the following lines to <code>bootstrap/less/panels.less</code></p>
  
  <pre><code>//hover color for panel heading
  .panel-heading:hover {
    background-color: #dfdfdf;
  }
  </code></pre>
  
  <p>But it wouldn't load to the css in the browser. yet I can manually add it in the css editor (in chrome dev tools) and it works. </p>
  
  <p>Any solutions  ? </p>