Travis-CI configuration

This pull request contains the necessary configuration file for travis-ci to work.

Travis will build on each new commit and pull request with three different JVMs. The build result is mailed to the commit author and the repository owner (Sebastian).
The email notification settings are controllable via the travis.yml file.

A full build with integration tests currently needs around 30 minutes. 
The web-viewer for the build results does only show the first 10k lines, but you can click the little wheel at the upper right corner which allows to download the full log (for example: https://s3.amazonaws.com/archive.travis-ci.org/jobs/9013766/log.txt)