Liveness indicates the server is up, and running.

Metrics serves metrics.

New is `Handler` factory.

NewReadinessDeterminer is the Readiness factory.

OK replies with `200` status code, and "OK" in the body.

Readiness indicates the server is up, running, and ready to work.

Stop allows the server to be remotely, and gracefully stopped.

Handler definition.

ReadinessDeterminer definition.