title: using react-native-elements for material Icons - does not recognise some of the icons
body: <p>using the snack below:
  <a href="https://snack.expo.io/ry_5rCk84" rel="noreferrer">https://snack.expo.io/ry_5rCk84</a></p>
  
  <p>I am trying to display the icon 'wifi_off' using Material Icons in my react native app (just shared this as a snack on expo for easier sharing) but this is not a recognised value for prop 'name'.
  and ends up displaying a '?' for unknown icon.
  I am able to use <strong>wifi-off</strong> icon using '<strong>material-community</strong>' icon set</p>
  
  <pre><code>import * as React from 'react';
  import { Text, View, StyleSheet } from 'react-native';
  import { Constants } from 'expo';
  import {Icon} from 'react-native-elements';
  
  // You can import from local files
  import AssetExample from './components/AssetExample';
  
  // or any pure javascript modules available in npm
  import { Card } from 'react-native-paper';
  
  export default class App extends React.Component {
    render() {
      return (
        &lt;View style={styles.container}&gt;
          &lt;Text style={styles.paragraph}&gt;
            Change code in the editor and watch it change on your phone! Save to get a shareable url.
          &lt;/Text&gt;
          &lt;Card&gt;
            &lt;AssetExample /&gt;
          &lt;/Card&gt;
          &lt;Icon name='wifi' size={50} type='material'/&gt;
          &lt;Icon name='wifi-off' size={50} type='material-community' /&gt;
          &lt;Icon name='wifi_off' size={50} type='material' /&gt;
        &lt;/View&gt;
      );
    }
  }
  
  const styles = StyleSheet.create({
    container: {
      flex: 1,
      justifyContent: 'center',
      paddingTop: Constants.statusBarHeight,
      backgroundColor: '#ecf0f1',
      padding: 8,
    },
    paragraph: {
      margin: 24,
      fontSize: 18,
      fontWeight: 'bold',
      textAlign: 'center',
    },
  });
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/5vLSO.png" rel="noreferrer"><img src="https://i.stack.imgur.com/5vLSO.png" alt="enter image description here"></a></p>