update webpack-dev-server dependency

client/package.json

@@ -76,7 +76,7 @@
         "url-loader": "1.0.1",
         "webpack": "4.1.1",
         "webpack-cli": "2.0.12",
-        "webpack-dev-server": "3.1.1",
+        "webpack-dev-server": "3.1.14",
         "webpack-merge": "4.1.2",
         "write-file-webpack-plugin": "4.2.0"
     }