release a version

Releases are to be done via maven.

1. set correctly the artifact version & SCM tag info
2. commit the change
3. release to sonatype OSS: mvn -Prelease clean deploy
4. verify the content of the staged repository: https://oss.sonatype.org/content/groups/staging
5. if ok then release the stage repository to deploy to central: mvn nexus-staging:release