title: How do I render square ListItem avatar instead of round?
body: <p>I need to render square avatar. How do I do it?</p>
  
  <p>I have implemented the listItem code as provided by react native element document: <a href="https://react-native-training.github.io/react-native-elements/docs/listitem.html" rel="nofollow noreferrer">https://react-native-training.github.io/react-native-elements/docs/listitem.html</a></p>
  
  <p>It works well but in this version of react native element 1.1.0 I don't know how to render square avatar instead of round.</p>
  
  <pre><code> &lt;ListItem
          title={item.name}
          subtitle={item.subtitle}
          leftAvatar={{ source: { uri: item.icon } }}
      /&gt;
  </code></pre>
  
  <p>I need to have left squar avatar filling the listview height.</p>