Instead of manually including composer's auto-loading
stuff and then run PHPUnit\TextUI\Command::main(), now
we are using the PHPUnit "binary".
That way behaviour should be 100% the same than
running vendor/bin/phpunit (recommended instead of util.php --run).
Also, note that, for other util.php commands, we still need
composer's auto-loading to happen, so we have moved it immediately
after the --run command.
Finally, a few more file_exists() conditions have been added
to ensure that PHPUnit is properly installed. Redundant but...
Eloy Lafuente (stronk7)
f192195a76