Bump webpack-cli from 3.1.0 to 3.1.2 in /js

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 3.1.0 to 3.1.2.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/master/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-cli/commits/v3.1.2)

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

js/package.json

@@ -30,7 +30,7 @@
     "mini-css-extract-plugin": "^0.4.3",
     "node-sass": "^4.9.3",
     "webpack": "^4.20.2",
-    "webpack-cli": "^3.1.0",
+    "webpack-cli": "^3.1.2",
     "webpack-merge": "^4.1.4"
   },
   "scripts": {