Use Alex Dreyer's librarian branch

librarian-puppet is not compatible with PE 3.2.  This commit
changes the code to temporarily use a branch that Alex Dreyer
made that makes it compatible.

Also fixes a few things for compatibility with the latest
puppet-gatling plugin
Merge pull request #76 from cprice404/maint/master/use-alex-dryers-librarian-branch

Use Alex Dreyer's librarian branch