fixing travis configuration for new container infrastructure and add the sass gem

.travis.yml

@@ -2,13 +2,20 @@ language: node_js
 
 node_js: 0.10.33
 
+sudo: false # use new container infrastructure
+
+# sass setup
+cache: bundler # speeds up bundler
+rvm:
+  - 2.2.2
+
 before_script:
   - npm install -g grunt-cli
-  - export DISPLAY=:99.0
-  - sh -e /etc/init.d/xvfb start
+  #- export DISPLAY=:99.0
+  #- sh -e /etc/init.d/xvfb start
   # Install meteor
-  - curl https://install.meteor.com | /bin/sh
+  #- curl https://install.meteor.com | /bin/sh
   # Install spacejam, Meteor's CI helper
-  - npm install -g spacejam
+  #- npm install -g spacejam
 
-script: grunt cibuild
+script: bundle install && grunt cibuild