* Correct capitalization inconsistency in DarkSky
All two-word sensors ("Precip Intensity," "Nearest Storm Bearing," etc) in Darksky uses title case for the friendly name of the sensor, with the exception of "Dew point."
* Implement UV Index in Darksky
* Fixed whitespace for Tox compliance
* Add unit for UV Index.
Per recommendation of reviewer, added 'UV Index' as a CONST in const.py, then used that const in both DarkSky and ISY994. It looks like BloomSky might also support UV Index and it should probably be standardized.
* Re-enabled Weather Sensors for the ISY component.
As the ISY component had been updated to support newer components and
have better UOM support, the support for ISY’s weather module was
dropped. This adds that support back into Home Assistant.
* Cleanup of the ISY Weather support.
Cleaned up the for loops used to generate nodes representing weather
data from the ISY. Moved the weather_node named tuple to the top of the
file so that it can be more easily identified.
* Update isy994.py
