Bump webpack-dev-server from 1.16.5 to 3.1.11

Bumps [webpack-dev-server](https://github.com/webpack/webpack-dev-server) from 1.16.5 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/compare/v1.16.5...v3.1.11)

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

package.json

@@ -186,7 +186,7 @@
     "stylus": "^0.52.4",
     "stylus-loader": "^2.3.1",
     "webpack": "^1.12.2",
-    "webpack-dev-server": "^1.12.0"
+    "webpack-dev-server": "^3.1.11"
   },
   "optionalDependencies": {
     "grunt-electron-installer-debian": "^0.5.0",