use local casperjs & update dev setup guide

Author: yyx990803

CONTRIBUTING.md

@@ -44,11 +44,10 @@ Hi! I’m really excited that you are interested in contributing to Vue.js. Befo
 
 ## Development Setup
 
-You will need [Node](http://nodejs.org), [Grunt](http://gruntjs.com), [PhantomJS](http://phantomjs.org) and [CasperJS](http://casperjs.org).
+You will need [Node.js](http://nodejs.org) & [Grunt](http://gruntjs.com).
 
 ``` bash
-# in case you don’t already these:
-# npm install -g grunt-cli phantomjs casperjs
+# npm install -g grunt-cli
 $ npm install
 ```
 
@@ -61,7 +60,7 @@ $ npm run dev
 To lint:
 
 ``` bash
-grunt jshint
+$ grunt jshint
 ```
 
 To build:
@@ -73,13 +72,11 @@ $ grunt build
 To test:
 
 ``` bash
-# if you don’t have these yet:
-# npm install -g phantomjs casperjs
 $ grunt test
 ```
 
-The unit tests are written with Jasmine and run with Karma. The functional tests are written for and run with CasperJS.
+The default task (by simply running `grunt`) will do the following: lint -> build -> unit tests -> e2e tests. It is required to have this pass successfully for a PR to be considered.
 
-**If you are not using a Mac**
+The unit tests are written with Jasmine and run with Karma. The e2e tests are written for and run with CasperJS.
 
-You can modify the Gruntfile to only run Karma tests in browsers that are available on your system. Just make sure don’t check in the Gruntfile for the commit.
+Note that the unit tests will automatically be run in Chrome, Firefox and Safari. If you are not on a Mac, or don't have one of the browsers installed on your system, you can modify the [karma config in gruntfile.js](https://github.com/yyx990803/vue/blob/dev/gruntfile.js#L42) to only run Karma tests in browsers that are available on your system. Just make sure don’t check in the gruntfile changes for the commit.

build/grunt-tasks/casper.js

@@ -8,7 +8,7 @@ module.exports = function (grunt) {
     var done = this.async()
     var file = id ? id + '.js' : ''
     grunt.util.spawn({
-      cmd: 'casperjs',
+      cmd: '../../node_modules/.bin/casperjs',
       args: ['test', '--concise', './' + file],
       opts: {
         stdio: ['ignore', process.stdout, 'ignore'],

package.json

@@ -21,6 +21,7 @@
     "dev": "webpack --watch --config build/webpack-dev-config.js & webpack --watch --config build/webpack-test-config.js"
   },
   "devDependencies": {
+    "casperjs": "^1.1.0-beta3",
     "grunt": "^0.4.5",
     "grunt-contrib-jshint": "^0.10.0",
     "grunt-karma": "^0.8.3",