Remove --silent option passed to Rubocop since it's no longer supported
Remove --silent option passed to Rubocop since it's no longer supported

Rubocop no longer supports the --silent option. Results in "invalid option: --silent"

https://github.com/bbatsov/rubocop/blob/f6159fae0f2713d26d7b7dc8c06e3f5bbf84f004/CHANGELOG.md

eitoball/rubocop-checkstyle_formatter