Reorganized as module and added new features.

[monokrome]

I doubt you'll want these changes, but figured that I'd pass them along in case you're interested since you started the project. If you do want them then I'd be happy to fix conflicts and work on getting it to a merging point!

• Can manually reroute ports in etcd
• Other settings are exposed as env variables including the prefix string used in etcd (in case backends isn't preferred)
• Added unit tests w/ CircleCI and coverage reporting with Coveralls
• Some other stuff

Thanks for making this open source!