Bump karma from 2.0.3 to 2.0.4 in /js

Bumps [karma](https://github.com/karma-runner/karma) from 2.0.3 to 2.0.4.
- [Release notes](https://github.com/karma-runner/karma/releases)
- [Changelog](https://github.com/karma-runner/karma/blob/master/CHANGELOG.md)
- [Commits](https://github.com/karma-runner/karma/compare/v2.0.3...v2.0.4)

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

js/package.json

@@ -25,7 +25,7 @@
     "babel-loader": "^7.1.2",
     "babel-preset-env": "^1.7.0",
     "css-loader": "^0.28.9",
-    "karma": "^2.0.3",
+    "karma": "^2.0.4",
     "mini-css-extract-plugin": "^0.4.0",
     "node-sass": "^4.5.3",
     "webpack": "^4.12.1",