First pass at getting an approach for VMC development vs VMC release

- Use HEAD of our libraries (cfoundry, mothership, plugins, etc) in dev via Gemfile

- Use stable versions of our libraries in released gem via gemspec

Change-Id: I1ef2c1ec4d779844b005df0d4644d6159f02ac8d
Merge "First pass at getting an approach for VMC development vs VMC release"