title: Why AppEventsLogger.logEvent is undefined?
body: <ul>
  <li>react-native: 0.40</li>
  <li>react-native-fbsdk: 0.5</li>
  </ul>
  
  <p>I want to use react-native-fbsdk in my React Native project to log events and I did all by instruction for this library. But when I tried to launch it on iOS emulator I got an error:</p>
  
  <blockquote>
    <p>undefined is not an object (evaluating 'AppEventsLogger.logEvent')</p>
  </blockquote>