title: Why does Checkbox fires Tabs onChange event in material-ui?
body: <p>I'm using <a href="http://www.material-ui.com/" rel="nofollow">Material UI</a> for React.</p>
  
  <p>I have a checkbox inside of a tab:</p>
  
  <pre><code>const Layout = () =&gt; (
  &lt;Tabs value='a' onChange={e =&gt; console.log(e)}&gt;
    &lt;Tab label='a' value='a'&gt;
      &lt;Checkbox /&gt;
    &lt;/Tab&gt;
  &lt;/Tabs&gt;
  );
  </code></pre>
  
  <p>When I click on the checkbox <code>Tabs</code>' <code>onChange</code> event gets fired. Is it intentional behavior? Is there a way to avoid this?</p>
  
  <p>Here is an example: <a href="https://github.com/evgeny-t/material-ui-webpack-example/compare/master...evgeny-t:checkbox-inside-tabs?expand=1" rel="nofollow">https://github.com/evgeny-t/material-ui-webpack-example/compare/master...evgeny-t:checkbox-inside-tabs?expand=1</a></p>