chore(package): update standard to version 12.0.1

Closes #25

Author: greenkeeper[bot]

package.json

@@ -33,7 +33,7 @@
   "devDependencies": {
     "mocha": "^5.0.0",
     "should": "^13.0.1",
-    "standard": "^11.0.0"
+    "standard": "^12.0.1"
   },
   "optionalDependencies": {},
   "bin": {