The process of deploying to maven central has been automated based on the Complete guide to continuous deployment to maven central from Travis CI and will be executed whenever a non-snapshot version is committed.
Is the build passing?
git checkout master
Also check if you can upgrade any dependencies:
mvn versions:display-dependency-updates
Now release everything:
mvn release:clean release:prepare
Ping a maintainer to deploy the release by running these commands:
git checkout vX.Y.Z
mvn clean deploy -Psign-source-javadoc