Update ROADMAP.md based on 10/21/2014 DGAB meeting

The Docker Governance Advisory Board (DGAB) met for the first time Tue 10/21/2014.  Among other topics, the DGAB reviewed and refreshed the Docker Project Statement of Direction.

Docker-DCO-1.1-Signed-off-by: Scott Johnston scott.johnston@docker.com (github: j0hnst0n)