Get same issue on my setup, BT LE was working on RAspbian + AIO but not using BT addon for Hass.io, seems to be linked to /tmp size on Hass.io that is not large enough to allow gatlib installation: Bluetooth LE not enabled?
Still looking for a fix on this for Hass.io to get my beacon back in HA.
2017-08-09 21:34:10 ERROR (SyncWorker_15) [homeassistant.util.package] Unable to install package gattlib==0.20150805: Command “python setup.py egg_info” failed with error code 1 in /tmp/pip-build-_fs32tnw/gattlib/
2017-08-09 21:34:10 ERROR (MainThread) [homeassistant.setup] Not initializing device_tracker.bluetooth_le_tracker because could not install dependency gattlib==0.20150805
2017-08-09 21:34:10 ERROR (MainThread) [homeassistant.setup] Unable to prepare setup for platform device_tracker.bluetooth_le_tracker: Could not install all requirements.
Did you have to do anything to get your Raspberry Pi3 enabled for Bluetooth tracking other than putting the following in your configuration.yaml file?
I did it however I can’t locate any devices. However if I use the inbuilt Raspberry Pi 3 bluetooth app, I can see some devices.