Add basic tests to the registry

[struys]

My team at Yelp would like become familiar with the registry to run it internally. We think a good way to get started would be to add a few tests to the project.

Are there any preferences around what testing library to use? We want to make sure our changes are upsteamable.

[wibblymat]

This would be awesome! The main bower repo uses mocha and expect.js, so that would be preferred to keep things unified.

[sheerun]

@struys I've updated repo so writing integration tests is more pleasurable.

Please see test/integration.js