Merge pull request reduxjs#827 from camsong/patch-3

Update combineReducers.md

Author: gaearon

docs/api/combineReducers.md

@@ -80,7 +80,7 @@ export default combineReducers({
 #### `App.js`
 
 ```js
-import { createStore, combineReducers } from 'redux';
+import { createStore } from 'redux';
 import reducer from './reducers/index';
 
 let store = createStore(reducer);