CleanWebpackPlugin is not a constructor解决方法

现在cleanwebpackplugin已经升级到了3.0.0了，所以以前的方法并不适用了。
新的方法：

const { CleanWebpackPlugin } = require('clean-webpack-plugin');
 
const webpackConfig = {
    plugins: [
        /**
         * All files inside webpack's output.path directory will be removed once, but the
         * directory itself will not be. If using webpack 4+'s default configuration,
         * everything under /dist/ will be removed.
         * Use cleanOnceBeforeBuildPatterns to override this behavior.
         *
         * During rebuilds, all webpack assets that are not used anymore
         * will be removed automatically.
         *
         * See `Options and Defaults` for information
         */
        new CleanWebpackPlugin(),
    ],
};