Is there Ruby code convention metric tool?

I have been found some ruby code convention metric tool, but cannot
yet.

rails_best_practice(https://github.com/flyerhzm/rails_best_practices)
is near by my needs, but not enough. That is for rails not ruby.

I'll use that tool for
- set ruby covention standards for my developer team.
- check convention metric our ruby code in our hudson.
- and improve code.

Would you recommend any tools for me?
thanks.