Fix test command in contribution guides

Wesley van der Sanden · kamilogorek · commit cb723ec24b1e · 2017-10-02T11:28:03.000+02:00
Closes #1065
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
@@ -51,7 +51,7 @@ The test suite is powered by [Mocha](http://visionmedia.github.com/mocha/) and c
 From the command line:
 
 ```bash
-$ grunt test
+$ npm run test
 ```
 
 From your browser:
diff --git a/docs/contributing.rst b/docs/contributing.rst
@@ -35,7 +35,7 @@ From the command line:
 
 .. code-block:: sh
 
-    $ grunt test
+    $ npm run test
 
 From your browser:
 
