Bump eslint from 6.8.0 to 8.21.0

Bumps [eslint](https://github.com/eslint/eslint) from 6.8.0 to 8.21.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/main/CHANGELOG.md)
- [Commits](eslint/eslint@v6.8.0...v8.21.0)

---
updated-dependencies:
- dependency-name: eslint
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -27,7 +27,7 @@
     "chai": "^4.2.0",
     "chai-as-promised": "^7.1.1",
     "coveralls": "^3.0.3",
-    "eslint": "^6.3.0",
+    "eslint": "^8.21.0",
     "eslint-config-standard": "^14.1.0",
     "eslint-plugin-import": "^2.16.0",
     "eslint-plugin-node": "^11.0.0",