2053 - Update CONTRIBUTING.md with new commands (#2055)

CONTRIBUTING.md

@@ -10,8 +10,7 @@ If a bug, please include the following —
 
 Please *do not* ask for support using the issue queue. For support, please ask [on chat](https://gitter.im/c3js/c3) or [the mailing list](groups.google.com/forum/#!forum/c3js).
 
-##Building C3 from sources
+## Setup
-
  1. **Clone the repo from GitHub**
 
         git clone https://github.com/c3js/c3.git
@@ -24,16 +23,21 @@ Please *do not* ask for support using the issue queue. For support, please ask [
 
     The first `npm` command sets up the popular [Grunt](http://gruntjs.com/) build tool. You might need to run this command with `sudo` if you're on Linux or Mac OS X, or in an Administrator command prompt on Windows. The second `npm` command fetches the remaining build dependencies.
 
- 3. **Run the build tool**
+## Building C3 from sources
+    npm run build
 
-        grunt
+
+## Distribution
+    npm run dist
 
 Now you'll find the built files in `c3.js`, `c3.min.js`, `c3.css` & `c3.min.css`.
 
 ## Running the tests
-The `grunt` script will automatically run the specification suite and report its results.
+    npm run test
+
+This command will automatically run the specification suite and report its results.
 
-Or, if you want to run the specs in a browser (e.g., for debugging), simply open `spec/runner.html` in your browser.
+If you want to see specs running live in browser (e.g., for debugging), simply open `http://localhost:9876/` in your browser when phantomjs starts.
 
 ## Contributing your changes