Subdomain exclusions

Impliments #83

Tests included :+1: 

You might note that I used a hack to get around the domain middleware. This is only because the sample app uses all three middlewares, and as the rack stack bubbles up the domain middleware tries to change the database  to the example schema which at the time doesnt exist as well. I created the schema because I don't know how to work around this fact without removing that middleware. I figure this is still okay because I'm not testing the domain middleware, that should be done by another test somewhere else and is treated more of a tack to maintain the consistency of the dummy app.

However if anyone knows how to do it without that hack let me know :).

However it works, as expected :tm: