Error: Rule can only have one resource source (provided resource and test + include + exclude) in {

首先卸载原来的webpack包：npm uninstall webpack
然后重新再项目中安装低版本的：npm install [email protected]^4.0.0 --save-dev

我自己的盲区小tips:
–save ： dependencies 键下，发布后还需要依赖的模块.
–save-dev ： devDependencies 键下,仅在开发时依赖的模块