App Rewrite: Remove CodeClimate code & stuff

[vovimayhem]

This project was created in a hurry. I ended copying some of the code climate code into this one, then changing stuff.

While implementing #9, I noticed most of the abstractions on CodeClimate are a bit clunky - at least for this project's goals. Also, the fact that CodeClimate can do with streaming the engine output directly to STDOUT, whereas Belugas can't do that (subsequent engines may depend on the previous engine output) makes other CodeClimate abstractions get in the way for our use case.

Maybe we can do much of the container management stuff using github.com/xeger/docker gem, remove the codeclimate gem & code, and have a much simpler codebase.