Keyremap4macbook is now karabiner

The boxen module has correspondingly changed name. See:

https://github.com/boxen/puppet-keyremap4macbook/commit/aa8dd790d601018c648f758e390baf79be4a6b36
[bradleywright] Update profile to use karabiner

The API is exactly the same, so a simple search/replace gets boxen
running again.
Merge pull request #110 from alphagov/switch-keyremap4macbook-to-karabiner

Switch keyremap4macbook to karabiner