- Fixed deprecation notices in PHP 8.1 for production code implementations:
-`ArrayAccess`
-`Countable`
-`IteratorAggregate`
- PHP 8.0 requirement in composer.json
- **Warning:** Tests are not updated, Cake's tests rely on old version of PHPUnit so running them may show a lot of deprecations notices. Added issue to cover it: #7
- Fixed ErrorHandler accordingly to PHP8 migration guide. Otherwise, error handler is logging too much and doesn't respect configured `error_reporting`.