added queue prefix to match the framework

[5.2] Added two symfony deps to require-dev

Applied fixes from StyleCI

Conflicts:
	config/mail.php

Set Mail pretend config from .env

Redis connection setup in .env

PSR-2 formatting of User model?

> Lists of implements MAY be split across multiple lines, where each subsequent line is indented once. When doing so, the first item in the list MUST be on the next line, and there MUST be only one interface per line.

https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md#41-extends-and-implements

Use same DB_CONNECTION enviroment variable for queue.failed.database config

Removed unused option

Remove unguard call

[5.1] Use $this instead of parent.