lib/snoo/subreddits.rb
def unban_user container, user, subreddit
      unfriend_wrapper container: container, name: user, r: subreddit, type: "banned"
    end
def unban_user container, user, subreddit
      unfriend_wrapper container: container, name: user, r: subreddit, type: "banned"
    end
Unban a user from a subreddit

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