Bump symfony/phpunit-bridge from 5.0.8 to 5.1.0

Bumps [symfony/phpunit-bridge](https://github.com/symfony/phpunit-bridge) from 5.0.8 to 5.1.0.
- [Release notes](https://github.com/symfony/phpunit-bridge/releases)
- [Changelog](https://github.com/symfony/phpunit-bridge/blob/master/CHANGELOG.md)
- [Commits](symfony/phpunit-bridge@v5.0.8...v5.1.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>