chore(package): update mocha to version 7.1.0

Closes #23

Author: greenkeeper[bot]

package.json

@@ -63,7 +63,7 @@
     "express": "^4.16.4",
     "jsdom": "^15.0.0",
     "live-server": "^1.2.1",
-    "mocha": "^6.1.4",
+    "mocha": "^7.1.0",
     "npm-run-all": "^4.1.5",
     "nyc": "^14.1.1",
     "postcss": "^7.0.14",