title: How to handle redux-form/CHANGE in reducer
body: <p>What is the recommended way to handle <code>redux-form/CHANGE</code> actions being dispatched by redux-form? I have my own reducer managing the state of this form but I'm not sure if it's best to do the following:</p>
  
  <pre><code>export default reducer (state = initialState, action) {
    case 'redux-form/CHANGE':
      // return modified state
  }
  </code></pre>
  
  <p>One problem I see is that this reducer would receive <em>every</em> <code>redux-form/CHANGE</code> action. Additionally as far as I can tell ActionTypes.js isn't exported in a way for me to import it so I feel as though this may not be best practice.</p>