Add puppetdb 2.0 compatibility + expose facts

This version now uses PuppetDB 2.x's REST interface including the specification of API version (uses v3, the stable version as of the time of this update).

Facts are also exposed as attributes so that filtering based on fact (attribute) values can be accomplished within the Rundeck GUI.
Update README.md
Update to fix spelling ;)
Merge pull request #2 from sirloper/master

Add puppetdb 2.0 compatibility + expose facts