chore(package): update supertest to version 3.0.0

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -49,7 +49,7 @@
     "rsvp": "3.5.0",
     "semantic-release": "^4.3.5",
     "standard": "^10.0.2",
-    "supertest": "^2.0.0",
+    "supertest": "^3.0.0",
     "xyz": "^1.0.0"
   },
   "standard": {