chore(package): update mocha to version 6.2.1

Closes #21

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "eslint-plugin-node": "^6.0.0",
     "eslint-plugin-promise": "^3.6.0",
     "eslint-plugin-standard": "^3.0.1",
-    "mocha": "^5.0.0",
+    "mocha": "^6.2.1",
     "sinon": "^5.0.0",
     "uuid-validate": "0.0.2"
   },