Update to latest Berks and TK; Lock to sane Rubocop
add windows_chef_zero TK provisioner

This will be point at the released version once a release is pushed to
RubyGems.org.
Add Windows 7 and 8.1 to `.kitchen.yml` platforms
Add Windows support to `_user` recipe
Add Windows support to `_git` recipe
Add Windows support to `_packaging` recipe
Create Windows provider for the `ruby_install` resource
Add Windows support to the `ruby_gem` resource
Add cross-platform support to `_ruby` recipe
Ensure Unix-y recipes are no-op on Windows
Perform user creation early in config process

We'll also move all .dotfile creation into the associated recipes.
Ensure recipes declare dep on chef-sugar
Remove `macosx-10.9` from TK platforms

Due to errors in the DSCL User provider `kitchen verify` does not pass.
We'll just remove the platform for the time being until we get time to
merge fixes into Chef core.
Fix spec coverage based on recent refactors
Add a group for the build user
Add integration test coverage for generated .dotfiles
Create platform specific scripts to load omnibus env
Update ServerSpec code to use `os` helper
Deploy `sign-rpm` script on RHEL platform family

This script makes it possible to do unattended RPM singing. The file
previously existed in one of CHEF’s private repos.
Merge pull request #35 from opscode-cookbooks/schisamo/assorted-fixes

Windows support, refactors and improvements