Bump phpunit/phpunit from 6.5.8 to 6.5.13
Bump phpunit/phpunit from 6.5.8 to 6.5.13

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 6.5.8 to 6.5.13.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/6.5.13/ChangeLog-6.5.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/6.5.8...6.5.13)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
php-api-clients/github