I created an example project for authentication and authorization in mezzio application. It uses acl. It featuring prg, csrf, flash, and rememberme functionality.
It can be used wth MySQL or PostgreSQL database.
The repository is at https://github.com/samsonasik/mezzio-authentication-with-authorization
You can give it a try by run:
composer create-project samsonasik/mezzio-authentication-with-authorization -sdev
and follow the readme.