PHPUnit 5, 6, 7

[Remi Collet]

Hi guys,

Fedora 26+ have php-phpunit-PHPUnit version 5.7.27
Fedora 27+ have phpunit6 version 6.5.6 (with a buildroot override)
Fedora 28+ have phpunit7 version 7.0.0

Thanks to Robert-André Mauchin for the fast reviews.

The whole PHPUnit stack now use range dependencies to avoid installation
issue (as we now have >2 versions of some components)

Cheers,
Remi