yeomain实践
yo generator安装：就是在每个模块前加 generator 如：
安装angular：
npm install -g generator-angulary
使用： yo + generaotr名称
如：yo angular testAngrular
根据提示安装你的项目
If you do npm config set production, then that sets the --production configuration flag for all npm commands, by setting production = true in the ~/.npmrc file.
If you do npm start --production, then it'll set the NODE_ENV=production environ for the start script.
If you do npm install --production then it won't install devDependencies locally.
