* Update deps
This also updates for the new (and required) paradigm for registering
service implementations as spelled out in
https://github.com/grpc/grpc-go/issues/3385
* Roll back dockertest
This was always an RPC-only distinction and from that perspective it
makes sense; however it causes the generated docs to treat it as an
entirely separate service even though it's under the same collection
path as auth methods and this is confusing.