Fix tests and change some objects

[Lash-L]

Changes:

• Removed async_setup - when configuration setup isn't done in yaml, it doesn't need to exist.
• Changed to OptionsFlowwithConfigEntry
• Created two fixtures to get either a mockconfigentry or a mock config entry that has been set up
• Changed how setup of entries works
• Instead of directly calling functions in init, we now use hass to call them

I will have to change either this Pr or the other depending on which gets merged first

[agittins]

I figured this one might be easier to rebase, so I merged the formatting PR first.

[agittins]

This is great, thanks! I was pretty baffled with the whole testing thing :-)

[agittins]

Awesome!