This change creates a contrib directory in the Cinder tree and adds
a project called block-box.
This addition provides a method to easily create Docker images for
a standalone Cinder deployment and employs a docker-compose file to
enable rapid build and deployment of Cinder as a standlone service.
Change-Id: Id08ffefd322e80a433b58d48b8b89b1ca1695150
db82e4450a