Introduced CelluloidTest as a test class for all tests that depend on
Celluloid being up and running.

We handle these errors nicely in the dispatcher and have tests for that.
Tests should fail or err out when running into exceptions we are not
handling yet. But for these it's better to just skip.

If one source raises a 502 and no other handler has any result we'll
respond with a 502 - bad gateway.

Dropped the webmock dependency. We have our own http adapter. So we can
stub that to inject a mock. As an added bonus this does not mess with
other http requests.

Also wrote down testing strategy. Not completely implemented yet.

Also changed Nickserver::Response to not include the status code.
This may be okay for error responses but in most cases we want to
have a parsable message and not some status code prepended to it.

require all the things we depend upon where we depend upon them.

So far we would error out if no host was specified in the config or
the request. It's true that we can't do local lookup if we don't
know our own domain. However we can still use HKP.

In the future we will query leaps own API for other providers. If the
host was not set in the initial request we might even proxy a request to
ourselves. Providing the Host header will prevent an infinite loop in
that case.