Setup continuous integration testing

[AndreMiras]

It would be great to have a CI such as Travis running.
It's really reassuring for user and contributors to see unit tests are in place and running automatically. It also an easy way to "document" consistently how tests are supposed to run.
To run tests in Travis, I would suggest you to run from a Docker container. Not only it provides isolations for tests, but also it makes it possible to decouple integration testing from the CI provider and last but not least contributors can use this Docker file to test their changes locally before pull requesting.