Bump eslint-loader from 3.0.4 to 4.0.2 in /token-swap/js (#96)

Bumps [eslint-loader](https://github.com/webpack-contrib/eslint-loader) from 3.0.4 to 4.0.2.
- [Release notes](https://github.com/webpack-contrib/eslint-loader/releases)
- [Changelog](https://github.com/webpack-contrib/eslint-loader/blob/master/CHANGELOG.md)
- [Commits](webpack-contrib/eslint-loader@v3.0.4...v4.0.2)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

token-swap/js/package.json

@@ -50,7 +50,7 @@
     "css-loader": "^3.1.0",
     "dotenv": "8.2.0",
     "eslint": "^6.1.0",
-    "eslint-loader": "^3.0.0",
+    "eslint-loader": "^4.0.2",
     "eslint-plugin-import": "^2.13.0",
     "eslint-plugin-react": "^7.11.1",
     "event-emitter": "^0.3.5",