title: Importing constants are undefined react redux
body: <p>I have something like this:</p>
  
  <pre><code>//ActionTypes.js
  export const a = 'a';
  
  //Reducer.js
  import a from './ActionTypes';
  //export reducer function that uses string a
  
  //Actions.js
  import a from './ActionTypes';
  return {type: a, data: 'something'}
  </code></pre>
  
  <p>but in both reducer.js and actions.js 'a' is undefined. There is no circular dependancy as far as i know. Pls help</p>