Create readiness and liveness checks for containerized operation

[smoyer64]

A container orchestration system needs to be able to assess whether the jms-reactive-client is operational and healthy. Candidates are:

1. A semaphore file (https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/#define-a-liveness-command)
2. Enable JMX on the reactive client and provide a tiny Java application to provide a zero/non-zero status code (https://docs.oracle.com/javase/tutorial/jmx/remote/custom.html)