Run puppet unit tests on newer 3.x series versions

Puppet has advanced beyond 3.4. This adds tests to be run
in 3.6 and 3.7. 3.7 will be the last 3.x release. We don't need
to test 3.5 because it only existed for 2 weeks and was replaced
quickly by 3.6 because of some terrible bugs. Verion 3.3 is the
oldest puppet we will test against.

Discussion here http://tinyurl.com/ocsz4hj

Change-Id: I59d55f2a7e796087fb614788b76f62d09a13f729
Merge "Run puppet unit tests on newer 3.x series versions"