chore(package): update @types/mocha to version 7.0.1

Closes #665

package.json

@@ -59,7 +59,7 @@
   },
   "devDependencies": {
     "@types/chai": "^4.0.3",
-    "@types/mocha": "^5.2.6",
+    "@types/mocha": "^7.0.1",
     "@types/node": "^13.1.0",
     "chai": "^4.1.0",
     "clean-webpack-plugin": "^1.0.1",