chore(package): update mocha to version 6.0.1

Closes #71

Author: greenkeeper[bot]

package.json

@@ -43,7 +43,7 @@
     "done-css": "^3.0.0",
     "express": "^4.13.4",
     "jquery": "2.x - 3.x",
-    "mocha": "^4.0.0",
+    "mocha": "^6.0.1",
     "nock": "^9.0.11",
     "recursive-copy": "^2.0.6",
     "request": "^2.69.0",