title: Toggle bootstrap button dropdown using another button
body: <p>Been having some issues getting a Bootstrap button dropdown to toggle (making the list items and dropdown ul element visible) when another button is clicked. Here's what I have so far which doesn't seem to work (v3.3.7). I want the "testing" button to additionally toggle the "test" button dropdown.</p>
  
  <pre><code>&lt;div class="btn-group"&gt;
      &lt;a id="test-dropdown-btn" class="btn btn-default dropdown-toggle" data-toggle="dropdown"&gt;
          Test &lt;span class="caret"&gt;&lt;/span&gt;
      &lt;/a&gt;
      &lt;ul id="test-dropdown" class="dropdown-menu"&gt;
          &lt;li&gt;&lt;a href="#"&gt;test&lt;/a&gt;&lt;/li&gt;
      &lt;/ul&gt;
  &lt;/div&gt;
  &lt;a id="test-btn" class="btn btn-default" onclick="$('#test-dropdown-btn').dropdown('toggle')"&gt;testing&lt;/a&gt;
  </code></pre>