chore(package): update mocha to version 6.1.4

Closes #37

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "grunt-contrib-copy": "^1.0.0",
     "grunt-contrib-uglify": "^3.0.0",
     "grunt-mocha-test": "^0.13.0",
-    "mocha": "^5.0.0",
+    "mocha": "^6.1.4",
     "request": "^2.42.0",
     "should": "^13.0.0",
     "tar": "^4.0.2"