title: className on Drawer component doesnt work
body: <p>I'm using react and material-ui and I have come across an issue, I want to define some css behavior for the drawer component, and I have read that it is quite simple, that all I have to do is use the className property, but for some reason it doesn't work.</p>
  
  <p>Here is my css:</p>
  
  <pre><code>.drawer {
      width: 200px
  }
  
  .drawer:hover {
      background-color: black
  }
  </code></pre>
  
  <p>Here is my usage of the drawer:</p>
  
  <pre><code>&lt;Drawer open={this.state.isLeftNavOpen}
                               docked={false}
                               className='drawer'
                               onRequestChange={this.changeNavState}&gt;
                          &lt;MenuItem primaryText='Men'
                                    onTouchTap={() =&gt; browserHistory.push({pathname: '/products', query: {category: MEN}})}/&gt;
                          &lt;MenuItem primaryText='Women'
                                    onTouchTap={() =&gt; browserHistory.push({pathname: '/products', query: {category: WOMEN}})}/&gt;
                          &lt;MenuItem primaryText='Kids'
                                    onTouchTap={() =&gt; browserHistory.push({pathname: '/products', query: {category: KIDS}})}/&gt;
                      &lt;/Drawer&gt;
  </code></pre>
  
  <p>I tried wrapping the Drawer with div but still no success.</p>
  
  <p>Any idea what I'm doing wrong?</p>