Add ability to use Bundler to run puppet-lint

If Gemfile exists, use Bundler to install dependencies and
run puppet-lint check. If Gemfile is missing, fallback to previous
behavior which is to use system packages instead.

Change-Id: I6dbb9a6977b568a71225f9cbc7d5715f6deab7cd
let puppet manage jenkins zmq-event-publisher plugin

The zmq-event-publisher has already been release[1] so letting puppet manage it.

[1] http://repo.jenkins-ci.org/repo/org/jenkins-ci/plugins/zmq-event-publisher/

Change-Id: Iaee1c5de7ed08d37f1080447ef255a4acc5808e5
Merge "Add ability to use Bundler to run puppet-lint"
Merge "let puppet manage jenkins zmq-event-publisher plugin"