Testing

Fixes an issue where tests won't run due to MiniTest being installed.

Unfortunately the attrs may come in different orders, preventing a reliable signature test (so I had to remove my attempt to test that for now).

If you want to setup Travis CI to test against multiple Rubies and on pull requests, just sign in and add a webhook (the YML file is provided).
http://docs.travis-ci.com/user/getting-started/