Add support for Consul

[hauleth]

[dnaeon]

Hey @hauleth,

I think that having support for Consul would be a great addition to Gru, but this point in time I don't see this one as a high-priority feature, as I'm focusing more on fleshing out some of the core functionality of the project - more resources, concurrency, etc.

I'd be more than happy to review and accept patches via pull request, so if anyone wants to pick this one up, that would be great.

@hauleth, would consider sending me some patches for Consul support if you are able to work on this one?

Thanks, Marin