chore(package): update eslint-config-prettier to version 6.9.0

Closes #19

Author: greenkeeper[bot]

package.json

@@ -27,7 +27,7 @@
     "has-yarn": "^1.0.0"
   },
   "devDependencies": {
-    "eslint-config-prettier": "^2.9.0",
+    "eslint-config-prettier": "^6.9.0",
     "husky": "^0.14.3",
     "jest": "^22.0.4",
     "lint-staged": "^7.0.0",