Update webpack-dev-server requirement from 3.2.0 to 3.2.1

Updates the requirements on [webpack-dev-server](https://github.com/webpack/webpack-dev-server) to permit the latest version.
- [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@v3.2.0...v3.2.1)

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

Author: dependabot-support

package.json

@@ -65,7 +65,7 @@
     "style-loader": "0.23.1",
     "webpack-cli": "3.3.0",
     "webpack": "4.29.6",
-    "webpack-dev-server": "3.2.0",
+    "webpack-dev-server": "3.2.1",
     "webpack-merge": "4.2.1"
   }
 }