chore(package): update standard to version 13.0.2

Closes #11

Author: greenkeeper[bot]

package.json

@@ -16,7 +16,7 @@
     "cross-env": "^3.1.3",
     "doctoc": "^1.2.0",
     "nyc": "^8.4.0",
-    "standard": "^8.5.0",
+    "standard": "^13.0.2",
     "uglify-js": "^2.6.4",
     "umd": "^3.0.1"
   },