chore(package): update mocha to version 6.1.4

Closes #4

Author: greenkeeper[bot]

package.json

@@ -32,7 +32,7 @@
   },
   "devDependencies": {
     "chai": "^4.1.2",
-    "mocha": "^5.1.1",
+    "mocha": "^6.1.4",
     "ts-node": "^6.0.3"
   }
 }