mod-permissions persistent storage needs to be migrated to Postgres

Since we are moving away from Mongo for Folio, the Auth module suite needs to follow suit.

Currently, the Login and Permissions modules use a Mongo backend for storage. (The Authtoken module does not currently use persistent storage).

As the Auth modules are NOT currently implemented using the RAML Module Builder, it is a valid question of whether we should reimplement the Auth modules in the RMB framework, or whether we should build our own interface with the Postgres database. We'll need to evaluate the limitations of the RMB and determine if there is any required functionality in the Auth modules that would be impeded by using the RMB. (On the other hand, it is possible that any such limitations could be worthy points for extending the RMB framework itself). A third way could be to split the code so that the CRUD operations are build with the RMB, while more complex logic is managed as a separate module.