Tasks for 4.0

[vv12131415]

As it may need to break things in 4.0 (which I will try not to do) some things should be added to this package

• [ ] phpstan (max level)
• [ ] psalm (level 1)
• [ ] 100% coverage
• [ ] support for latest versions only (php and composer require)
• [ ] declare(strict_types=1)
• [ ] do not use helpers and facades (but provide them, since some people will like to use it). Try to use interfaces

the list may be expanded...

[Germey]

@vladyslavstartsev Hi, hopes things go well, are there anything updates for this package? Thanks~