Add configuration for Travis-CI.

This will allow automated builds on every commit or pull request. To enable it please sign up for [Travis CI](https://travis-ci.org) and enable the service for the *tuxmobil/CampFahrplan* repository. The next commit being pushed to GitHub should trigger a build.

Right after please add the beautiful Travis CI badge for the project to the top of the `README.md`. Feel free to adapt the code from [here](https://github.com/johnjohndoe/TypedPreferences/blob/master/README.md). the badge will reflect the current build status for every visitor. This could be the "next" commit to trigger the build.