chore(package): update eslint-config-airbnb to version 18.0.1

Closes #28

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
     "cross-env": "^5.2.0",
     "css-loader": "^1.0.0",
     "eslint": "^5.2.0",
-    "eslint-config-airbnb": "^17.0.0",
+    "eslint-config-airbnb": "^18.0.1",
     "eslint-plugin-babel": "^5.1.0",
     "eslint-plugin-flowtype": "^2.50.0",
     "eslint-plugin-import": "^2.13.0",