remove grunt install from travis

Author: bmuenzenmeyer

.travis.yml

@@ -9,7 +9,6 @@ before_install:
   - phantomjs --version
 
 before_script:
-  - npm install -g grunt-cli
   - npm install patternengine-node-underscore
   - npm install patternengine-node-handlebars
   - npm install patternengine-node-twig