rvm安装
$ curl -L get.rvm.io | bash -s stable
$ source ~/.bashrc
$ source ~/.bash_profile
$ rvm install 2.0.0
测试是否正确
$ ruby -v
ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-darwin13.0.0]$ gem -v
2.1.6$ gem source -r https://rubygems.org/
$ gem source -a http://ruby.taobao.org
$ gem install rails 然后测试安装是否正确
$ rails -v
Rails 3.2.13 
