build(deps-dev): bump eslint from 7.20.0 to 7.21.0 (#177)

Bumps [eslint](https://github.com/eslint/eslint) from 7.20.0 to 7.21.0.
- [Release notes](https://github.com/eslint/eslint/releases)
- [Changelog](https://github.com/eslint/eslint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eslint/eslint/compare/v7.20.0...v7.21.0)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -42,7 +42,7 @@
     "@typescript-eslint/eslint-plugin": "^4.15.2",
     "@typescript-eslint/parser": "^4.15.2",
     "@zeit/ncc": "^0.22.3",
-    "eslint": "^7.20.0",
+    "eslint": "^7.21.0",
     "eslint-config-prettier": "^8.1.0",
     "eslint-plugin-import": "^2.22.1",
     "eslint-plugin-prettier": "^3.3.1",