chore(package): update eslint-config-airbnb to version 18.1.0

Closes #1

Author: greenkeeper[bot]

package.json

@@ -51,7 +51,7 @@
     "chai": "^4.2.0",
     "cross-env": "^5.2.0",
     "eslint": "^6.1.0",
-    "eslint-config-airbnb": "^17.1.1",
+    "eslint-config-airbnb": "^18.1.0",
     "eslint-plugin-import": "^2.18.2",
     "eslint-plugin-jsx-a11y": "^6.2.3",
     "eslint-plugin-react": "^7.14.3",