chore(package): update eslint-config-airbnb to version 12.0.0 (#20)

Author: greenkeeperio-bot

package.json

@@ -22,7 +22,7 @@
   },
   "devDependencies": {
     "eslint": "^3.5.0",
-    "eslint-config-airbnb": "^11.1.0",
+    "eslint-config-airbnb": "^12.0.0",
     "eslint-plugin-import": "^1.15.0",
     "eslint-plugin-jsx-a11y": "^2.2.2",
     "eslint-plugin-react": "^6.2.2"