add ~/.rbenv/bin to /home/jduan/.rbenv/shims:/home/jduan/.tools-cache/home/aurora/tools/client/bin/:/Applications/Racket_v6.0/bin:/usr/local/heroku/bin:/usr/local/bin:/usr/local/sbin:/usr/local/share/npm/bin:/home/jduan/.rbenv/bin:/home/jduan/scripts:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games