Travis-CI and Coveralls support

This pull request:

* Adds support for Travis-CI unit testing
* Adds support for Coveralls coverage
* Adds badges for Travis and Coveralls to the README file
* Fixes #13 - Missing test requirements
 
There are two manual steps required to complete once this pull request is merged:

* Activate the github hook: https://travis-ci.org/profile
* Add the repo to: https://coveralls.io/  (see add repo button)