Bump phpunit/php-code-coverage from 5.0.0 to 5.2.0

Bumps [phpunit/php-code-coverage](https://github.com/sebastianbergmann/php-code-coverage) from 5.0.0 to 5.2.0.
- [Release notes](https://github.com/sebastianbergmann/php-code-coverage/releases)
- [Changelog](https://github.com/sebastianbergmann/php-code-coverage/blob/5.2.0/ChangeLog-5.2.md)
- [Commits](sebastianbergmann/php-code-coverage@5.0.0...5.2.0)

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

Author: dependabot-support