Add simple travis-ci integration

**A simple  .travis.ym for building eudaq.**
Like here: https://travis-ci.org/themperek/eudaq

One need to setup travis-ci for the project: http://docs.travis-ci.com/user/getting-started/

Does not include GUI and ROOT for the moment..
Can change notifications: http://docs.travis-ci.com/user/notifications/
Can/Should add unit tests for automatic checking after every build.

Cheers,
Tomek