move version to __init__

[pinkywafer]

move version number to init.py, to allow resources to be downloaded by custom_updater.
Change sensor.py to be a resource
bump version

[pinkywafer]

@swetoast Can you please Revert this PR. I'm afraid I had not checked closely enough into the way pyupdate pulls updates. as the repo name is sensor.rpi_power, the customjson generator will always use rpi_power/sensor.py as the base and as a result, pyupdate will currently ignore any resources and download nothing else. I have a pull request on pyupdate with a suggested work around, which if it works as intended, would need to undo this PR. This seems like the best approach to me, as the only alternative I can see is to change the way the customjson generator works, but that would also require every component to be altered to suit.

[swetoast]

Reverted :)