I did the Python Virtualenv install on a Raspberry PI.
Both of the below were installed within the venv:
HomeAssistant 0.40.1
pyatv 0.2.2
log snippet:
17-03-17 19:13:28 ERROR (MainThread) [homeassistant.setup] Not initializing media_player.apple_tv because could not install dependency pyatv==0.2.1
17-03-17 19:13:28 ERROR (MainThread) [homeassistant.setup] Unable to prepare setup for platform media_player.apple_tv: Could not install all requirements.