something new:
install git:

sudo apt-get install git

don’t install from ppa anymore.
install rvm: run the command from official website,the latest version,maybe not the stable version.
install ruby:we don’t use version 1.9.3 anymore，search the official website，the latest version,for exemple:2.3.1 the old version may got some problem when install the gem package.
rubygems bundle installits address has change,the latest version isRuby China，we could check it out from the origin official website.