#1 Updated the way artifacts get published to Nexus.

Previous way with `uploadArchives` seems to be deprecated according to
internets. New Publishing DSL is replacing it. Required plugins:
- `publishing` - a general API that uses some of underlying impls
- `maven-publish` - a particular implementation if Publishing
- `maven-publish-auth` - is needed to pass creds from settings.xml rather
 than hardcode them. Note, that if settings.xml is not in ~/.m2, then it
 should be passed as -Dmaven.settings=/blah/settings.xml.