chore(package): update eslint-config-prettier to version 6.4.0

Closes #11

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "micro": "^9.1.0"
   },
   "devDependencies": {
-    "eslint-config-prettier": "^2.9.0",
+    "eslint-config-prettier": "^6.4.0",
     "xo": "^0.20.2"
   },
   "xo": {