(PUP-3119) Added yaml output to puppet resource

This enables you to list resources in YAML format for copy/paste into Hiera files.

The output should be suitable for use with the create_resources function
It is pretty much a copy of to_manifest, I just changed the output format of the original function.

I'm an ops guy scratching his own itch, I haven't got a clue how to do what you ask, sorry!