remove webpack-dev-server

Author: freewind

package.json

@@ -25,7 +25,6 @@
     "typescript": "^3.0.3",
     "webpack": "^4.18.0",
     "webpack-cli": "^3.1.0",
-    "webpack-dev-server": "3.1.8",
     "webpack-serve": "^2.0.2"
   }
 }