steal workstation cookbook with roles and data bags from jtimberman's workstation-chef-repo

https://github.com/jtimberman/workstation-chef-repo
add Berksfile to provide external cookbooks
add Berksfile.lock to .gitignore
mapping caps lock to control isn't important to me

also this would merely log a helpful message on osx
I'll rewrite user management later if necessary, conveniently remove rbenv stuff
remove reads of users data bag
simple cookbook to create /usr/local for homebrew
update dependencies in workstation metadata.rb

add missing mac_os_x cookbook
add usrlocal cookbook
consolidate to a single workstation role, remove extraneous items to speed testing
remove extraneous items from workstation data bag item to speed testing