API rate buckets, defaulting to the frontend host

[cmc333333]

Different API paths can be tagged with different bucket names. These bucket names will be used when determining how to count rate limit requests. By default, these rate limits will be bucketed by frontend host name.

We'll need a corresponding pull request to the admin interface to allow this bucket to be defined explicitly.

Relates to 18F/api.data.gov#124

[GUI]

Nice, thanks for tackling this!

I just added a couple of additional tests for scenarios this all handled perfectly fine, but I wanted to double check and have in our test quite. I also tweaked some text in the tests slightly. Explained here: 7086e75

Even without the admin capabilities, I'd be game to deploy this to production, since I think it gives us much better defaults. Do you have any availability today or tomorrow when maybe we could work to do the deployment together? That will help make sure I get all your server accounts setup and you have proper access everywhere to do deployments.