Updated Docker to v0.7.6.
Merge pull request #51 from opdemand/docker-0.7.6

Updated Docker to v0.7.6, tested.
skip docker steps if already installed

This will reduce lookups to get.docker.io on chef runs
* save a small amount of time for chef runs
* if get.docker.io is unavailable it won't break run.
Merge pull request #55 from paulczar/fix_docker

skip docker steps if already installed
Merge pull request #59 from appcubator/runtime-cleanup2

Cleanup inactive runtime slugs
Merge pull request #60 from appcubator/runtime-cleanup2

Fix caching of the slugs
fix typo in runtime slug test
Merge remote-tracking branch 'deis/master'
updatez