Merge branch 'master' into patch-1

docs/source/tutorial/client.md

@@ -130,7 +130,7 @@ Open `src/index.js` and add the following lines of code:
 
 _src/index.js_
 
-```js
+```js lines=1,4,6
 import { ApolloProvider } from 'react-apollo';
 import React from 'react';
 import ReactDOM from 'react-dom';