Run lint and syntax stackforge/puppet-* checks on trusty

Puppet module lint and syntax tests should also be run on trusty along
with unit tests. This patch adds lint and syntax tests to the regex to
skip assigning stable/icehouse branch tests to trusty nodes.

Change-Id: Id7f091678f0140f0d4feb9c317d653ac79b43d58
Merge "Run lint and syntax stackforge/puppet-* checks on trusty"