npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
修改npm包所安装目录的权限：sudo chown -R $USER /usr/local 然后输入密码就可以了
npm WARN checkPermissions Missing write access to /usr/local/lib/node_modules
原文：https://www.cnblogs.com/jimmy1293/p/10822802.html