Merge pull request #11 from Naturalclar/chore/upgradeWebpack

chore: update webpack dev-server

Author: haruelrovix

package.json

@@ -87,7 +87,7 @@
  "terser-webpack-plugin": "1.1.0",
  "url-loader": "1.1.1",
  "webpack": "4.19.1",
- "webpack-dev-server": "3.1.9",
+ "webpack-dev-server": "3.9.0",
  "webpack-manifest-plugin": "2.0.4",
  "workbox-webpack-plugin": "3.6.3"
  },