sources from git snapshot
add dependency on sebastian/cli-parser
add dependency on phpunit/php-file-iterator
drop depency on sebastian/finder-facade
drop depency on symfony/console

raise depency on PHP 7.3
raise depency on sebastian/finder-facade 2
raise depency on sebastian/version 3
allow symfony 5

raise dependency on PHP 7.2
add dependency on php-json
only allow Symfony 4
use phpunit8 for upstream test suite