get mvn release:rollback to delete tag in GIT

This is currently not supported by the Maven Release Plugin.

See here: http://maven.apache.org/maven-release/maven-release-plugin/examples/rollback-release.html

The created branch/tag in SCM for the release is removed. Note: This is not yet implemented so you will need to manually remove the branch/tag from your SCM. For more info see MRELEASE-229.

The ticket (https://issues.apache.org/jira/browse/MRELEASE-229) has been open since 2007.

Depending on the problem that caused mvn release:perfom to fail, you can also just not rollback the release and after having fixed the problem run mvn release:perform directly, without running mvn release:prepare.