chore(package): update mocha to version 7.2.0

Closes #141

package.json

@@ -54,7 +54,7 @@
     "karma-phantomjs-launcher": "~1.0.0",
     "karma-safari-launcher": "~1.0.0",
     "karma-sauce-launcher": "~1.1.0",
-    "mocha": "~4.1.0",
+    "mocha": "~7.2.0",
     "phantomjs-prebuilt": "~2.1.3",
     "watchify": "^3.7.0"
   }