Clean up Dockerfile

* Combine apt-get commands
* Add DEBIAN_FRONTEND=noninteractive and -q flags to apt-get calls
* Eliminate warnings on adduser call
* Remove unneeded chown
* Combine install Ruby 2.1.2 during RVM install
Rearrange .gemrc creation, let RVM install bundler
Provision deploy user and RVM in separate images
Rename to base-ubuntu12.04-deploy*
Call apt-get clean after apt-get install
Add python-software-properties to base image
Add Dockerfiles for 14.04 base images
Add \ in front of curl as per RVM docs

(Avoids shell aliasing for "curl")
Merge pull request #1 from synctree/split-bases

Split bases