Initial Development

Oops. Originally I was just checking that SubscribeEmail objects were EventEmitters by checking if they had an `emit` method. I've got other, more specific Event tests in the User Interaction tests that are run with the web driver (https://github.com/blocks/subscribe-email/blob/MmLRZ2E2-development/test/selenium-driver.js#L81) so I'm just going to rever this one to checking for the `emit` method.