Add a parent POM when another tool is developed

[smoyer64]

If we decide to use a parent POM, the two build jobs will need to be pointed at pom.xml (they're currently pointing at jms-reactive-client/pom.xml).

As an alternative, we can version each tool individually by building each module within the SCM system as its own job. If we choose this alternate path, we should rename the jms-tools-develop and jms-tools-release script to jms-reactive-client-develop and jms-reactive-client-release.