Unify win-*nix image bootstrapping method

[ScottBailey]

Windows and Linux/OSX each have different files to perform a bootstrap. These methods are diverging and the windows bootstrap.bat file is not sufficient to create a image for testing. Additionally, some regression tests depend on the *nix bootstrap.sh file to pass.

The bootsrap.sh file should be rewritten in python to simplify long term maintenance.

Additionally, Dockerfile.unix and Dockerfile.win are the same and should simply be renamed to Dockerfile which seems to be the Docker default.

This is low priority but necessary for windows testing.

[stephenpdeos]

OS X CLI utilities are not modern so the bootstrapping file doesn't work for it.