ruby的安装
系统存在多个ruby版本的情况下，建议使用rvm
Install rvm
$ bash < <(curl -s https://rvm.beginrescueend.com/install/rvm)
Load RVM into your shell sessions as a function 其实就是在.bash_profile里写一句话
user$ echo '[[ -s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load RVM function' >> ~/.bash_profile
Reload shell Configuration
user$ source .bash_profile
Install ruby with rvm
user$ rvm install 1.9.2
select ruby version
user$ rvm use 1.9.2 user$ rvm use system
安装rails
user$ gem install rails
安装bundler
user$ bundle install