not cache tweets
delete robots.txt
update README.md
remover user's most favorited/retweeted
compact Tweet
update schema.rb
fix tweets view; pagination
speed up discovered_by
update search query
move ApplicationController#_get_user to User.get
fix;;;
fix: snowflake_min to class method
update rss format
fix favoriters layout when can't load image
fix users/stats
ruby 2.0.0