fix: upgrade webpack-dev-server from 3.7.2 to 3.10.3

Snyk has created this PR to upgrade webpack-dev-server from 3.7.2 to 3.10.3.

See this package in NPM:
https://www.npmjs.com/package/webpack-dev-server

See this project in Snyk:
https://app.snyk.io/org/luisalejandro/project/b71a9271-9b95-498b-8074-fe63f95f575d?utm_source=github&utm_medium=upgrade-pr

Author: snyk-bot

package.json

@@ -78,7 +78,7 @@
     "webapp-webpack-plugin": "2.7.1",
     "webpack": "4.41.5",
     "webpack-cli": "3.3.5",
-    "webpack-dev-server": "3.7.2",
+    "webpack-dev-server": "3.10.3",
     "webpack-merge": "4.1.0",
     "webpack-pwa-manifest": "4.1.1",
     "yarn": "1.22.0"