Add mode options

Author: gedorinku

build/webpack.dev.conf.js

@@ -14,6 +14,7 @@ const HOST = process.env.HOST
 const PORT = process.env.PORT && Number(process.env.PORT)
 
 const devWebpackConfig = merge(baseWebpackConfig, {
+  mode: 'development',
   module: {
     rules: utils.styleLoaders({ sourceMap: config.dev.cssSourceMap, usePostCSS: true })
   },

build/webpack.prod.conf.js

@@ -15,6 +15,7 @@ const BrotliPlugin = require('brotli-webpack-plugin')
 const env = require('../config/prod.env')
 
 const webpackConfig = merge(baseWebpackConfig, {
+  mode: 'production',
   module: {
     rules: utils.styleLoaders({
       sourceMap: config.build.productionSourceMap,