chore(package): update standard to version 8.6.0 (#16)

Author: greenkeeperio-bot

package.json

@@ -11,7 +11,7 @@
     "ava": "^0.17.0",
     "coveralls": "2.x",
     "nyc": "10.0.0",
-    "standard": "8.4.0",
+    "standard": "8.6.0",
     "webpack": "^1.13.0"
   },
   "engines": {