npm管理员身份install时出现权限问题
在用npm安装模块时，虽然我是通过管理员身份执行的，但依然会报有关权限的错
The operation was rejected by your operating system.
npm ERR! It's possible that the file was already in use (by a text editor or antivirus),
npm ERR! or that you lack permissions to access it.
npm ERR!
npm ERR! If you believe this might be a permissions issue, please double-check the
npm ERR! permissions of the file and its containing directories, or try running
npm ERR! the command again as root/Administrator (though this is not recommended).
这是因为我手贱升了个级，升到了最新的5.3.0。升级之后应该在install后面加上–no-optional
所以说，同志们，不要盲目最求最新版本
