Bump eslint-config-prettier from 3.6.0 to 6.4.0

Bumps [eslint-config-prettier](https://github.com/prettier/eslint-config-prettier) from 3.6.0 to 6.4.0.
- [Release notes](https://github.com/prettier/eslint-config-prettier/releases)
- [Changelog](https://github.com/prettier/eslint-config-prettier/blob/master/CHANGELOG.md)
- [Commits](prettier/eslint-config-prettier@v3.6.0...v6.4.0)

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

package.json

@@ -59,7 +59,7 @@
     "cssnano": "^4.1.0",
     "eslint": "^5.4.0",
     "eslint-config-airbnb": "^17.1.0",
-    "eslint-config-prettier": "^3.0.1",
+    "eslint-config-prettier": "^6.4.0",
     "eslint-plugin-import": "^2.14.0",
     "eslint-plugin-jsx-a11y": "^6.1.1",
     "eslint-plugin-prettier": "^2.6.2",