[WIP] Mvn optional on java, Maven templates use ranges for parent pom

[BarDweller]

Checklist:

• Read the Code of Conduct and Contributing Guidelines.

• Followed the commit message guidelines.

• Stack adheres to Appsody stack structure.

Modifying an existing stack:

• Updated the stack version in stack.yaml

Notes

Tested on platforms..

• Linux
• Windows

References

Will address Issue #229 by using ranges for microprofile and spring-on-liberty stacks.

[BarDweller]

Note: back to WIP, as hard to test currently because the builds of microprofile & Spring-on-liberty are timing out in travis because the apt-get update is taking >10mins with no output.
Potentially the main travis yaml for this repo may need to use travis_wait to invoke the build script to allow longer time to build. As per https://docs.travis-ci.com/user/common-build-problems/#build-times-out-because-no-output-was-received

[BarDweller]

I'll split this into 3 PRs tomorrow (one per stack)

[BarDweller]

Superseded by PRs #329, #330, #331, #332, #333