title: getInitialState not working in Movies Tutorial
body: <p>Trying to follow the React Native tutorial with the Movies app.
  Using iOS or Android everything goes fine until we try to introduce state into the component.
  The tutorial does not use ES6 classes but the Hello World App does and this is where it gets confusing.</p>
  
  <p>The tutorial says to add <code>getIntialState</code> which breaks I assume due to using ES6 classes, however using a constructor also does not seem to work so I wanted to know what is the correct way to proceed?</p>
  
  <h3>Tutorial</h3>
  
  <pre><code>getInitialState: function() {
    return {
      movies: null,
    };
  },
  </code></pre>
  
  <h3>ES6 Equivalent?</h3>
  
  <pre><code>constructor(props) {
    super(props);
    this.state = {
      movies: null,
    };
  },
  </code></pre>