chore: Update Travis configuration to run Karma through Grunt

Running Grunt from within Travis allows us to lint the code in addition to
firing off the standard suite of unit tests.

.travis.yml

@@ -1,11 +1,13 @@
  language: node_js
  node_js:
    - "0.8"
+   - "0.10"
 
  before_install:
   - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start
-  - npm install -g [email protected] bower
+  - npm install -g karma bower grunt-cli
   - bower install
+  - npm install
 
- script: "testacular start test/test.conf.js --browsers=Firefox,PhantomJS"
+ script: "grunt"