title: Can not use global styles in styled-components
body: <p>I am trying to setup global styles in react-native. 
  I have imported</p>
  
  <p><code>import {injectGlobal} from 'styled-components';</code></p>
  
  <p>and have</p>
  
  <pre><code>class XoxoContainer extends Component {
    render() {
      return &lt;Xoxo {...this.props} /&gt;
    }
  }
  
  
  injectGlobal`
    font-family: '20'
  `;
  </code></pre>
  
  <p>But I keep getting <code>styledComponents.injectGlobals is not a function.</code> in the console.</p>