所以首先我创建了一个文件夹并创建了一个 ruby 文件并首先安装了 rpsc，它说安装成功，但是当我想运行规范命令时它说找不到命令。
Jonys-MacBook-Pro:rspec_tutorial JonyIve$ gem install rspec
Successfully installed rspec-2.12.0
1 gem installed
Installing ri documentation for rspec-2.12.0...
Installing RDoc documentation for rspec-2.12.0...
Jonys-MacBook-Pro:rspec_tutorial JonyIve$ spec user_spec.rb
-bash: spec: command not found