Adding tests, rockspec file, and TravisCI integration

This pull request includes a `rockspec` file for the project, and two tests built with `busted` that can be extended in the future. It also includes a `.travis.yml` file for [Travis CI](https://travis-ci.org), and an updated `README.md` file that shows the status of the latest build.

### Enabling Travis CI

In order to enable the Travis CI builds, a TravisCI webhook needs to be applied to the repository. That will trigger Travis CI on every push to the `master` branch. Once this is done, the first line of the `README.md` file needs to be updated too, to point to the proper build image, so that this text:

`[![Build Status](https://api.travis-ci.org/thefosk/classic.png)](https://travis-ci.org/thefosk/classic)`

becomes:

`[![Build Status](https://api.travis-ci.org/rxi/classic.png)](https://travis-ci.org/rxi/classic)`