Artefacts are published to Sonatype OSS, which sync's with Maven Central repositories.
The following procedure is executed manually:
$ sbt +test # tests the code
$ git tag vX.Y.Z -m "release version X.Y.Z"
$ sbt +publishSigned #publishes the signed artefacts to Sonatype staging
$ sbt sonatypeRelease
$ git push --tags origin develop