We're providing a local test server for the consul backends, so we might
as well use it to make the provider acceptance tests more relible as
well.
TODO: the TLS test doesn't actualy test anything other than the Config.
The tests have been modified to make it apparent that they aren't
connecting to the server at all.
This new resource is an alternative to consul_keys that manages all keys
under a given prefix, rather than arbitrary single keys across the entire
store.
The key advantage of this resource over consul_keys is that it is able to
detect and delete keys that are added outside of Terraform, whereas
consul_keys is only able to detect changes to keys it is explicitly
managing.