chore(package): update prettier-standard to version 9.1.1

Closes #12

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "husky": "^0.14.0",
     "lint-staged": "^4.2.1",
     "mocha": "^4.0.0",
-    "prettier-standard": "^6.0.0",
+    "prettier-standard": "^9.1.1",
     "semantic-release": "^7.0.1",
     "standard": "^11.0.0"
   },