Update dependency eslint-config-airbnb-base to v15

Author: renovate[bot]

package.json

@@ -20,7 +20,7 @@
     "chai": "4.3.4",
     "cross-env": "7.0.3",
     "eslint": "7.25.0",
-    "eslint-config-airbnb-base": "14.2.1",
+    "eslint-config-airbnb-base": "15.0.0",
     "eslint-config-prettier": "8.3.0",
     "eslint-plugin-import": "2.22.1",
     "eslint-plugin-prettier": "3.4.0",