chore(package): update standard to version 8.0.0 (#4)

Author: greenkeeperio-bot

package.json

@@ -10,7 +10,7 @@
     "os-homedir": "^1.0.1"
   },
   "devDependencies": {
-    "standard": "^7.1.2",
+    "standard": "^8.0.0",
     "semantic-release": "^4.3.5",
     "greenkeeper-postpublish": "^1.0.0"
   },