Puppet Forge release 2.0.0

  Marks the commit that the branch stable/grizzly and the 2.0.0 tag is
  cut from, adds the pkg directory to .gitignore to prevent accidental
  committing of Forge artifacts to the repository, updates release notes
  seciton of the README.

Change-Id: Icca41d9448833de35776395eaf2ab6c50a717956