add support for travis-ci rebuild WITHOUT redeploy if rebuilding a RELEASE version

[mbohun]

Since we changed (reverted to default) the nexus maven repo configuration, redeployment of already existing artefacts is disabled, and travis-ci.org reports build | failing for rebuild. This can/should be handled by the .travis file, by adding a simple if guard, that will at the end of every build:

• check if the current build is a release (war/zip version without -SNAPSHOT)
  • check if the release already exist in the maven repo
  • if the release does exist it will skip the deploy step, and output some status/warning msg to stdout

This would be best added to ala_common.sh every ALA .travis file should source.

[mbohun]

This feature is still "kinda" relevant, for example if we add support to other alternative CI systems like:

• https://circleci.com
• https://bitbucket.org/product/features/pipelines
• some Jenkins box

Already existing RELEASE version of some artifact in a repo is not necessary an error, perhaps we can file/URL detect it and notify the perpetrator/culprit (developer) to double-check if they want to.