Automatically close and promote release in Sonatype on release:perform

[massdosage]

At the moment performing a Maven release still requires manual steps of logging in to Sonatype and then closing and releasing the artifacts. This can be done as part of release:perform by using a plugin like so:

org.sonatype.plugins nexus-staging-maven-plugin 1.6.3 true sonatype-nexus-staging https://oss.sonatype.org/ true