refactor new action for polymorphic comments undefined method user_name bug
add votes_count to comments
fix bug: assign vote to user before save
order root_comments by votes_count DESC
add new comments to seeds
reduce font size of reply links
sort children by votes_count
refactor associations
add will_paginate gem
add pagination to @posts resources
paginate 30 posts per page
render pagination links
add default value to post.rank
create set_rank method