Bump php-coveralls/php-coveralls from 2.1.x-dev to 2.4.2

Bumps [php-coveralls/php-coveralls](https://github.com/php-coveralls/php-coveralls) from 2.1.x-dev to 2.4.2.
- [Release notes](https://github.com/php-coveralls/php-coveralls/releases)
- [Changelog](https://github.com/php-coveralls/php-coveralls/blob/master/CHANGELOG.md)
- [Commits](https://github.com/php-coveralls/php-coveralls/commits/v2.4.2)

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