Test start / stop. And check if the mocked function is really called

docs/api/examples/post_vpcs.txt

@@ -21,5 +21,5 @@ X-ROUTE: /vpcs
     "project_uuid": "a1e920ca-338a-4e9f-b363-aa607b09dd80",
     "script_file": null,
     "startup_script": null,
-    "uuid": "009a7260-e44c-4349-8df7-08668a3c4e17"
+    "uuid": "6370f75e-0a48-4e2b-95a8-0140da6ef1fb"
 }