Integrate gating unit tests to puppet modules

This commit adds unit tests that can serve as a minimal
gate that verifies the Puppet modules work on the following
versions of Puppet:
  - 2.6
  - 2.7
  - 3.0
  - 3.1

and builds jenkins jobs for the following modules:

  - cinder
  - nova
  - glance
  - horizon
  - openstack
  - swift

The unit tests are implemented as a job-group in jenkins job builder
with a single project called puppet-module-unit that is set as the
check and gate for the stackforge projects.

Change-Id: I61684bf150e572adaf3e9d9ae67f22d409f9afa4
Reviewed-on: https://review.openstack.org/26148
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Reviewed-by: Dan Bode <bodepd@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Reviewed-by: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins