title: How to update the button title?
body: <pre><code>&lt;DropdownButton bsStyle="default" title="No caret" noCaret id="dropdown-no-caret"&gt; 
    &lt;MenuItem eventKey="1"&gt;Action&lt;/MenuItem&gt;
    &lt;MenuItem eventKey="2"&gt;Another action&lt;/MenuItem&gt;
    &lt;MenuItem eventKey="3"&gt;Something else here&lt;/MenuItem&gt;
    &lt;MenuItem eventKey="4"&gt;Separated link&lt;/MenuItem&gt;
  &lt;/DropdownButton&gt;
  </code></pre>
  
  <p>I took this example from the react-bootstrap components examples, <a href="https://react-bootstrap.github.io/components.html#btn-dropdowns-nocaret" rel="nofollow">https://react-bootstrap.github.io/components.html#btn-dropdowns-nocaret</a></p>
  
  <p>How would you update the button title when one of the menu item is selected?</p>