Use travis-ci for tests

[BjoernSchotte]

While using Github as the repo for the new backend, it might also be a great idea to use travis-ci.org for automated tests

[DSB]

Nice idea - travis-ci is a good approach.
But we already have setup a local vm using Jenkins. We will get a sponsered public server soon and are ready to publish the setup there. Maybe we will try travis-ci later on if it leaves the alpha state (and if we find time to learn how to configure it properly).