1：安装vue脚手架时报这样的错
npm WARN checkPermissions Missing write access to C:\Users\liuyg\AppData\Roaming\npm\node_modules\vue-cli\node_modules\cliui\node_modules\wordwrap
npm ERR! path C:\Users\XXX()\AppData\Roaming\npm\node_modules\vue-cli\node_modules\cliui\node_modules\wordwrap
npm ERR! code ENOENT
npm ERR! errno -4058
npm ERR! syscall access
npm ERR! enoent ENOENT: no such file or directory, access 'C:\Users\liuyg\AppData\Roaming\npm\node_modules\vue-cli\node_modules\cliui\node_modules\wordwrap'
npm ERR! enoent This is related to npm not being able to find a file.
npm ERR! enoent
npm ERR! A complete log of this run can be found in:
npm ERR! C:\Users\XXX\AppData\Roaming\npm-cache\_logs\2017-10-18T14_34_23_721Z-debug.log
解决办法 ： 不是很明白，网上搜索讲 貌似是代理问题；
a:换一个npm安装源就好了，具体方法如下：npm config set registry https://registry.npm.taobao.org
npm info underscore
截图如下 ：
b:npm --registry https://registry.npm.taobao.org info underscore
截图如下 ：
c:npm run build
截图如下 ：
d:npm run dev
截图如下 ：
