Support PHPUnit 10

[mstrelan]

Closes #12

[acbramley]

Working now. First 3 are on phpunit10, second are phpunit9

skpr@b1cfcf46df40:data $ ./bin/phpunit-finder unit kernel | wc -l
32
skpr@b1cfcf46df40:data $ ./bin/phpunit-finder functional | wc -l
433
skpr@b1cfcf46df40:data $ ./bin/phpunit-finder functionaljavascript | wc -l
49
skpr@b1cfcf46df40:data $ ./bin/phpunit-finder unit kernel | wc -l
32
skpr@b1cfcf46df40:data $ ./bin/phpunit-finder functional | wc -l
433
skpr@b1cfcf46df40:data $ ./bin/phpunit-finder functionaljavascript | wc -l
49