KeyError: 'devices' in notify.py line 102 in targets

[alandtse]

Describe the bug
If notify runs before media_player is initialized, it reports a key error.

To Reproduce
Steps to reproduce the behavior:
Restart with notify loading first:

2019-09-02 08:58:31 INFO (MainThread) [custom_components.alexa_media] Loaded alexapy==1.0.1,
2019-09-02 08:58:34 INFO (MainThread) [homeassistant.setup] Setting up alexa,
2019-09-02 08:58:34 INFO (MainThread) [homeassistant.setup] Setup of domain alexa took 0.0 seconds.,
2019-09-02 08:58:41 WARNING (MainThread) [homeassistant.setup] Setup of alexa_media is taking over 10 seconds.,
2019-09-02 08:58:43 INFO (MainThread) [homeassistant.setup] Setup of domain alexa_media took 12.0 seconds.,
2019-09-02 08:58:43 INFO (MainThread) [homeassistant.components.notify] Setting up notify.alexa_media,
  File "/config/custom_components/alexa_media/notify.py", line 102, in targets,
2019-09-02 08:59:29 INFO (MainThread) [homeassistant.components.media_player] Setting up media_player.alexa_media,
2019-09-02 08:59:29 INFO (MainThread) [homeassistant.components.notify] Setting up notify.alexa_media,
2019-09-02 08:59:29 INFO (MainThread) [homeassistant.components.alarm_control_panel] Setting up alarm_control_panel.alexa_media,
2019-09-02 08:59:29 INFO (MainThread) [homeassistant.components.switch] Setting up switch.alexa_media

Traceback (most recent call last):
  File "/usr/src/homeassistant/homeassistant/components/notify/__init__.py", line 122, in async_setup_platform
    if hasattr(notify_service, "targets"):
  File "/config/custom_components/alexa_media/notify.py", line 102, in targets
    ['devices']['media_player'].items()):
KeyError: 'devices'

Expected behavior
No key error.

Screenshots
If applicable, add screenshots to help explain your problem.

System details

• Home-assistant (version):
• Hassio (Yes/No): (Please note you may have to restart hassio 2-3 times to load the latest version of alexapy after an update. This looks like a HA bug).
• alexa_media (version from const.py or HA startup):
• alexapy (version from pip show alexapy or HA startup):

Additional context
https://community.home-assistant.io/t/echo-devices-alexa-as-media-player-testers-needed/58639/3139