Add a fullblown testing server. This allows us to do integration tests.
Also add a basic proxy test. Further tests will test etcd proxy
and stub zone communication and other "wildish" configurations.
Redo the server startup, so we can access the ports it listens on when
it has started up (with dns.ActivateAndServer).
Extend the .travis file to download etcd and test for that as well.
Put integration tests in test dir
This implements stubzones in the same way as SkyDNS. This
also works with multiple configured domains and has tests.
Also add more configuration parameters for TLS and path prefix and
enabling stubzones. Run StubUpdates as a startup command to keep up to
date with the list in etcd.