lib/snoo/subreddits.rb
def remove_contributor container, user, subreddit
      unfriend_wrapper container: container, name: user, r: subreddit, type: "contributor"
    end
def remove_contributor container, user, subreddit
      unfriend_wrapper container: container, name: user, r: subreddit, type: "contributor"
    end
Remove a contributor from a subreddit

 @param (see #remove_moderator)
 @return (see #clear_sessions)