Add configurable repo/branch

[elia]

This helps in keeping the issues within the project repo vs. the gaskin app.

No specs unfortunately, I can add them if this change makes sense :)

[bkeepers]

Definitely on the right track. I'm not sure I like the idea of using a yaml config, but I hadn't really though through what the config would look like. I'd say keep going, add some tests, and we can change it later if we settle on something else.