Add nexus deployment settings for staging
Add nexus deployment settings for staging

Previously we only added the settings for snapshots, so when I was
trying to release RedDeer 0.6.0, the deploy command failed.
This should fix it. The definition is copied from the jbosstools
parent pom.

djelinek/reddeer,jboss-reddeer/reddeer,djelinek/reddeer,jboss-reddeer/reddeer