Bump webpack-dev-server from 2.11.5 to 3.1.11

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 2.11.5 to 3.1.11.
- [Release notes](https://github.com/webpack/webpack-dev-server/releases)
- [Changelog](https://github.com/webpack/webpack-dev-server/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-dev-server/commits/v3.1.11)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package.json

@@ -21,7 +21,7 @@
     "html-webpack-plugin": "^2.16.0",
     "style-loader": "^0.13.2",
     "webpack": "3.12.0",
-    "webpack-dev-server": "2.11.5"
+    "webpack-dev-server": "3.1.11"
   },
   "dependencies": {
     "draft-js": "0.10.1",