title: Error with Jest and React navigation in React Native
body: <p>I'm having problems when doing <strong>unit tests</strong> with <strong>jest</strong>:</p>
  
  <blockquote>
    <p>Invariant Violation: Native module cannot be null.</p>
  
  <pre><code>  at invariant (node_modules/fbjs/lib/invariant.js:42:15)
    at new NativeEventEmitter (node_modules/react-native/Libraries/EventEmitter/NativeEventEmitter.js:35:7)
    at Object.&lt;anonymous&gt; (node_modules/react-native-google-analytics-bridge/src/Helpers/FunctionCallTagHandler/index.io
  </code></pre>
    
    <p>s.js:16:37)
          at Object. (node_modules/react-native-google-analytics-bridge/src/GoogleTagManager.js:2:1)</p>
  </blockquote>