bump webpack-dev-server to 3.11.0 (facebook#8975)

Co-authored-by: Marc Hassan <marc@unqork.com>

Author: mhassan1

packages/react-scripts/package.json

@@ -79,7 +79,7 @@
     "ts-pnp": "1.2.0",
     "url-loader": "2.3.0",
     "webpack": "4.43.0",
-    "webpack-dev-server": "3.10.3",
+    "webpack-dev-server": "3.11.0",
     "webpack-manifest-plugin": "2.2.0",
     "workbox-webpack-plugin": "4.3.1"
   },