chore(deps): update dependency mocha to v8

Author: renovate-bot

package.json

@@ -40,7 +40,7 @@
     "karma-sauce-launcher": "4.1.4",
     "karma-sourcemap-loader": "0.3.7",
     "lint-staged": "10.2.9",
-    "mocha": "7.2.0",
+    "mocha": "8.0.1",
     "npm-run-all": "4.1.5",
     "phantomjs-prebuilt": "2.1.16",
     "prettier": "2.0.5",