util/release,script: Support releasing vagrant images

Signed-off-by: Lewis Marshall <lewis@lmars.net>
Merge pull request #295 from flynn/release-system

Support releasing Vagrant VirtualBox images
util/packer: Refactor scripts and use single JSON template

Signed-off-by: Lewis Marshall <lewis@lmars.net>
slugbuilder: Bump buildpacks

- Fix Play 1.x support
- Version bumps and minor bugfixes for other runtimes

Signed-off-by: Jonathan Rudenberg <jonathan@titanous.com>
Merge pull request #352 from flynn/bump-buildpacks

slugbuilder: Bump buildpacks
Merge pull request #351 from flynn/release-system

util/packer: Refactor scripts and use single JSON template
pkg, appliance, bootstrap: Solves #50 combined self signed certificate generation

Signed-off-by: Corey Powell <mistdragon100@gmail.com>