chore(package): update eslint-config-airbnb to version 8.0.0

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -40,7 +40,7 @@
   "devDependencies": {
     "coffee-script": "^1.8.0",
     "eslint": "^2.0.0",
-    "eslint-config-airbnb": "^6.0.1",
+    "eslint-config-airbnb": "^8.0.0",
     "tap": "^5.2.0",
     "touch": "^1.0.0"
   }