shouldn't that be ```/rest/registry/device``` ?

Otherwise, if the PushConfig's ```pushServerURI``` is like ```http://testreg.com/ag-push``` (no ```/``` at the end), I think the 
```UrlUtils.appendToBaseURL()``` will generate ```http://testreg.com/ag-pushrest/registry/device``` instead of ```http://testreg.com/ag-push/rest/registry/device```.