title: React Material-UI checkbox onChange event does not fire
body: <p>Trying to use Material UI checkbox. Pretty simple one might think? Well the checkbox doesn't toggle. Turns out the onChange event is not fired even internally to the component (I put logs in the node_modules package).</p>
  
  <pre><code>      &lt;Checkbox
          checked={this.state.isTrue}
          onChange={e =&gt; {
            console.log(e.target.checked);
            this.setState({isTrue: e.target.checked});
          }} /&gt;
  </code></pre>
  
  <p>Pretty simple, right? But the <code>console.log</code> never fires. I can hack around it by putting an <code>onClick</code> event handler on the component and toggling the state manually, but that is silly. Anyone have a clue?</p>
  
  <p>The API is at <a href="https://material-ui.com/api/checkbox/#checkbox" rel="noreferrer">https://material-ui.com/api/checkbox/#checkbox</a>. Not rocket science. </p>