Rack dependency issue

[andrebalazs55]

Is your feature request related to a problem? Please describe.

Hey!
I wanted to upgrade my app to include rubocop-rails gem.
I encountered with the problem that the rack gem has became a runtime dependancy instead of a development one.
In this case for us, it basically means a rails 5 dependancy, so basically we are not able to upgrade.

Describe the solution you'd like

Is there a way to be backward compatible with rack? Or will rubocop have an option to include the rails cop further?

[bbatsov]

See #68

[andrebalazs55]

thanks your answer! i was only searching in between the issues not in the prs. i close this since it is a duplicate.