API Request and Response

[marcotroisi]

Define the API request and response in JSON format for this microservice.

This microservice has certain APIs, request and response in place already. But they can probably be improved, and they should be updated to work in the same way as our other APIs in the other microlib microservices. As a reminder, for all our microlib microservices we adopt the JSON API specification.

Put it simply, we're going to build our own APIs leveraging the existing business logic of this microservice.

A starting point can be the document we already have on the usermanager: https://github.com/microlib/usermanager/blob/master/README.md