Support PHP 8

[h-o-sein]

Your requirements could not be resolved to an installable set of packages.

  Problem 1
    - Root composer.json requires php ^7.3 but your php version (8.0.10) does not satisfy that requirement.
  Problem 2
    - fzaninotto/faker is locked to version v1.9.2 and an update of this package was not requested.
    - fzaninotto/faker v1.9.2 requires php ^5.3.3 || ^7.0 -> your php version (8.0.10) does not satisfy that requirement.


Installation failed, reverting ./composer.json and ./composer.lock to their original content.