chore(deps): update dependency mocha to v8.4.0

[skip ci]

Author: renovate-bot

package-lock.json

@@ -55,7 +55,7 @@
     "eslint-plugin-standard": "4.1.0",
     "husky": "4.3.8",
     "lint-staged": "10.5.4",
-    "mocha": "8.3.2",
+    "mocha": "8.4.0",
     "mock-require": "3.0.3",
     "nyc": "15.1.0",
     "nyc-config-common": "1.0.1",