Bump rubocop-rails from 2.4.1 to 2.4.2
Bump rubocop-rails from 2.4.1 to 2.4.2

Bumps [rubocop-rails](https://github.com/rubocop-hq/rubocop-rails) from 2.4.1 to 2.4.2.
- [Release notes](https://github.com/rubocop-hq/rubocop-rails/releases)
- [Changelog](https://github.com/rubocop-hq/rubocop-rails/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rubocop-hq/rubocop-rails/compare/v2.4.1...v2.4.2)

Signed-off-by: dependabot-preview[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
diowa/ruby2-rails5-bootstrap-heroku,diowa/ruby2-rails5-bootstrap-heroku,diowa/ruby2-rails5-bootstrap-heroku