fix(travis): add coverage

Author: a8m

.travis.yml

@@ -5,4 +5,5 @@ before_script:
   - 'npm install -g grunt-cli'
   - 'npm install -g bower'
   - 'bower install'
-script: grunt test
+script: grunt test
+after_script: "npm install coveralls@2.10.0 && cat ./coverage/lcov.info | coveralls"