title: Eslint reports Flow Types as syntax error
body: <p>In cases where I'm using flow..
  <a href="https://flowtype.org/" rel="noreferrer">https://flowtype.org/</a></p>
  
  <pre><code>// @flow
  var foo = (str: string) =&gt; {
    return str;
  };
  </code></pre>
  
  <p>and Eslint together, 
  Eslint reports unexpected token on <code>str: string</code>.</p>
  
  <p>Is there a way to make Eslint ignore (or recognize) flow types and not report them as errors?</p>