Bump webpack-dev-server from 2.11.1 to 3.1.11

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 2.11.1 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](webpack/webpack-dev-server@v2.11.1...v3.1.11)

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

package.json

@@ -116,7 +116,7 @@
     "react-test-renderer": "^16.8.3",
     "sinon": "^1.17.7",
     "sinon-chai": "^2.8.0",
-    "webpack-dev-server": "^2.11.1"
+    "webpack-dev-server": "^3.1.11"
   },
   "publishr": {
     "dependencies": [