Clean up bundles after jenkins builds

We currently create git-bundles of the project when calling 'pl:jenkins:*' but
don't clean them up, or the build_params file. This commit adds that cleanup.

Signed-off-by: Moses Mendoza <moses@puppetlabs.com>
Merge pull request #130 from MosesMendoza/maint/master/cleanup_jenkins_bundles

Clean up bundles after jenkins builds