title: angular material md-button not working on firefox
body: <p>I have some problem when I'm implement's md-button on angular material. On chrome href is working but on firefox not working. This is my code:</p>
  
  <pre><code>&lt;md-button aria-label="signin" class="md-icon-button mdbtn120px"&gt;
    &lt;a href="#/sign_in" class="btn-custom"&gt;&lt;b&gt;SIGN IN&lt;/b&gt;&lt;/a&gt;
  &lt;/md-button&gt;
  </code></pre>