How to release:
If you haven't done this before, create a GPG key and push it out into the world.
Before the release, remember to update the README.md example version.
j7 mvn -Prelease release:prepare
j7 mvn -Prelease release:perform -Darguments="-Dmaven.deploy.skip=true"
git push --tags
Upload files from target/checkout/target to https://oss.sonatype.org/ as a Staging Upload.
Release the passed staging repo from the confusing UI.
(j7, j8 and j9 simply set the correct Java version PATH and JAVA_HOME for the command.)