Update dependency eslint-config-prettier to v6.15.0

Author: renovate[bot]

package.json

@@ -49,7 +49,7 @@
     "eslint": "^7.1.0",
     "eslint-config-airbnb": "18.1.0",
     "eslint-config-airbnb-base": "14.1.0",
-    "eslint-config-prettier": "6.11.0",
+    "eslint-config-prettier": "6.15.0",
     "eslint-config-xo": "0.29.1",
     "eslint-plugin-import": "2.20.2",
     "eslint-plugin-jsdoc": "25.2.0",