Are push notifications for iOS using `http://push-test.mattermost.com` working?

Hi all,

I set up Mattermost and all is working perfectly despite the mobile notifications. I enabled push notifications on the settings with the push notification server pointing to http://push-test.mattermost.com.

I see in the logs that the server is sending a push notification:
2016/04/22 11:03:15 UTC] [DEBG] Sending push notification to xxxx wi msg of 'xxxx sent you a direct message'

but I never get the notification in my iPhone.

Is this supposed to work? How can I debug further?

Thanks

Andreu