Merge branch 'travis_mongodb2_6' into improve_tests

.travis.yml

@@ -1,10 +1,12 @@
 language: node_js
 node_js:
   - '0.10'
-services:
-  - mongodb
+before_install:
+  - "sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10"
+  - "echo 'deb http://downloads-distro.mongodb.org/repo/ubuntu-upstart dist 10gen' | sudo tee /etc/apt/sources.list.d/mongodb.list"
+  - "sudo apt-get update"
+  - "sudo apt-get install mongodb-org-server"
 before_script:
   - 'npm install -g grunt-cli mocha'
-  - export DISPLAY=:99.0
-  - sh -e /etc/init.d/xvfb start
   - cp config.json.example config.json
+  - "until nc -z localhost 27017; do echo Waiting for MongoDB; sleep 1; done"