There are next changes:
- Minimum PHP version supported upgraded to 7.4 (#29)
- PHPUnit version upgraded to 9 (#29)
- Add run unit tests Github action (#30, #31)
- Remove travis (#30)
- Fix code style issues (#32)
- Fix by workaround grumphp issue with TypeError, see phpro/grumphp#957 (#32)
- Update friendsofphp/php-cs-fixer to 3 (#33)
- Add psalm (#34, #35)
- Add check cs github action (#36)