Bump webpack-dev-middleware from 1.12.0 to 5.3.4 in /vue-material

Bumps [webpack-dev-middleware](https://github.com/webpack/webpack-dev-middleware) from 1.12.0 to 5.3.4.
- [Release notes](https://github.com/webpack/webpack-dev-middleware/releases)
- [Changelog](https://github.com/webpack/webpack-dev-middleware/blob/v5.3.4/CHANGELOG.md)
- [Commits](webpack/webpack-dev-middleware@v1.12.0...v5.3.4)

---
updated-dependencies:
- dependency-name: webpack-dev-middleware
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

vue-material/package.json

@@ -78,7 +78,7 @@
     "vue-template-compiler": "2.4.3",
     "webpack": "3.5.6",
     "webpack-bundle-analyzer": "3.6.0",
-    "webpack-dev-middleware": "1.12.0",
+    "webpack-dev-middleware": "5.3.4",
     "webpack-hot-middleware": "2.19.1",
     "webpack-merge": "4.1.0"
   },