Update the JSON scheme to provide additional information

[rnelson0]

The JSON right now is pretty limited, just a list of privs. Add additional data to the schema to support description and other information that be useful to humans or computers.

[rnelson0]

Initial draft of the scheme at https://github.com/rnelson0/vCenter-roles/tree/expanded_json. Will iron on the schema before changing the code.

[rnelson0]

Rough PR at #13. Need some review before I merge it.