add travis config

### What is the problem / feature ?

No continuous integration

### How did it get fixed / implemented ?

I added a `.travis.yaml` file and enabled the project on travis-ci.com

### How can someone test / see it ?

Got to https://travis-ci.org/Apogaea/voldb and see that the the tests are being run

*Here is a cute baby animal picture for your troubles...*

![chicken-puppies_1589839i 1](https://f.cloud.github.com/assets/824194/2366643/5545a312-a714-11e3-945b-a6bb65f85e30.jpg)