(PDB-1034) Switch to using a script in the repo for PR testing

This switches us to using a script sources from the PuppetDB repo for PR
testing instead of storing the script in the jenkins job. This allows us
to easily do very different things if the branch is different, and will
prepare us for the PDB-1034 work where the actions required to bootstrap
testing for stable/master will be slightly different.

Signed-off-by: Ken Barber <ken@bob.sh>
Set gem.{summary,description,license} with appropriate values
Package only puppetdb-terminus files with gem.files and to not require
git to do so.
Merge pull request #1177 from deadpoint/master

Update puppetdb-terminus.gemspec to only package terminus files
Merge pull request #1176 from kbarber/ticket/stable/pdb-1034-prepare-pr-job-for-ezbake-migration

(PDB-1034) Switch to using a script in the repo for PR testing
Merge branch 'stable'

* stable:
  (PDB-1034) Switch to using a script in the repo for PR testing
(PDB-1034) Ezbake pr testing

Signed-off-by: Ken Barber <ken@bob.sh>