fix(package): update eslint-config-airbnb-base to version 12.0.2

Closes #6

Author: greenkeeper[bot]

package.json

@@ -12,7 +12,7 @@
   "dependencies": {
     "ajv": "^5.2.2",
     "eslint": "^3.19.0",
-    "eslint-config-airbnb-base": "^11.2.0",
+    "eslint-config-airbnb-base": "^12.0.2",
     "eslint-config-standard": "^10.2.1",
     "eslint-plugin-import": "^2.7.0",
     "eslint-plugin-node": "^5.1.0",