chore(package): update standard to version 9.0.2

Closes #7

https://greenkeeper.io/

Author: greenkeeper[bot]

Diff for: package.json

@@ -40,6 +40,6 @@
   "devDependencies": {
     "assertit": "^0.1.0",
     "istanbul": "^0.4.5",
-    "standard": "^8.5.0"
+    "standard": "^9.0.2"
   }
 }