Use puppet-arcanist, reducing duplication

Summary:
puppet-arcanist was spun out into a separate module so that it can be
used to install just arcanist.

Test Plan: Automated tests pass.

Reviewers: #macpros_internal, jbowman

Reviewed By: #macpros_internal, jbowman

Subscribers: jbowman

Differential Revision: http://phabricator.macprofessionals.lan/D21