Version 4.0.0 requires phpunit/php-code-coverage version ~4.0||~5.0 but attempts to use code from version 5 regardless.

Lines 82 - 84 of CodeCoverageExtension:

case 'xml':
    $reports['xml'] =  new Report\Xml\Facade(Version::id());
    break;

This doesn't work because class SebastianBergmann\CodeCoverage\Version was only added in version 5.0.0. I'm using 4.0.8 and I'm getting a fatal error instead. An upgrade is not an option, since I'm stuck with PHPUnit 5.7 which requires phpunit/php-code-coverage ^4.0.4 (legacy codebase).

Class Report\Xml\Facade doesn't expect any constructor arguments which means that Version::id() part can be safely removed.

Is there a chance a fix could be released as a 4.0.1? I could fix the issue myself but there's no v4.0 branch to create a pull request to.