Research how to deal with doze mode on Android 6
Android 6 has a new doze mode when the device is idle. Apps can't access the network in doze mode, except during short wakeup periods. This will kill our ability to receive messages while the device is idle. The recommended workaround is to use Google Cloud Messaging, which obviously won't work for us.
We may need to prompt the user to add Briar to a whitelist. Thanks Google! Love ya!