Bump eslint from 6.3.0 to 6.4.0 in /js

Bumps [eslint](https://github.com/eslint/eslint) from 6.3.0 to 6.4.0.
- [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/v6.3.0...v6.4.0)

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

js/package.json

@@ -54,7 +54,7 @@
     "apollo-link-error": "^1.1.11",
     "chai": "^4.2.0",
     "dotenv-webpack": "^1.7.0",
-    "eslint": "^6.0.1",
+    "eslint": "^6.4.0",
     "graphql-cli": "^3.0.12",
     "node-sass": "^4.11.0",
     "sass-loader": "^8.0.0",