Create a prototype for Oso Authorization library

[hbooth]

Oso is an Authorization framework for Python found here: https://docs.osohq.com/index.html

A prototype to gain familiarity with the library as well as to demonstrate how to build authorization policies in a Flask application with REST endpoints. The prototype will be similar to #222 in that it will need to be a Flask python application using Flask Login for authentication and has one or more simple endpoints. Example will have a permissions model similar to what is described in #89.

Definition of Done

• [ ] Example application that leverages Oso library
• [ ] Demonstrates secure/best practices for Oso library
• [ ] Has examples of a user granted and denied access based on group membership according to #89

[keithmanville]

See PR #297 and the abyrne-oso-schema-updates branch. Will re-visit at a later point.