Added Blimp namespace, Composer support, and unit test scaffolding

Added a few things to work better within the PHP ecosystem, and to help start with unit testing. Let me know if any of these changes need tweaking in order to merge. Cheers!

Note: I believe you'll need to register the library on packagist.org as blimp/client in order for the Composer support to work correctly, and setup a Github hook to travis-ci.org for them to run the automated tests.