参考http://stackoverflow.com/questions/26238884/brew-versions-unkown-command-mavericks
设定以后提示
Error: The `versions` command is no longer supported.
You can use the homebrew-versions tap instead:
https://github.com/Homebrew/homebrew-versions
解决方案如下
1，安装homebrew-versions
命令：sudo brew tap homebrew/versions
2，brew查看软件版本
命令：brew install homebrew/versions/mongodb
提示如下：
These similarly named formulae were found:
homebrew/versions/mongodb24 homebrew/versions/mongodb26
To install one of them, run (for example):
brew install homebrew/versions/mongodb24
3，安装
brew install homebrew/versions/mongodb24