Use environment's JAVA_HOME for Jetty config file
Installs and tests ckanext
Add Travis-CI
Allows recipes to be run without Vagrant

This is to be used by Travis-CI, to test the recipes without needing to use a
VM.
Creates user if it doesn't exist
Stop Postgresql before running on Travis

If we don't, we get an error when running chef, as we install another
postgres version.