Geomagindices

add test case for known missing date in FTP data 2011-01-01

work with modern Pandas. Simplify internals. This is an interim release till I can implement the PR with new data. Thanks for your patience.

this avoids contaminating many days rolling average with NaN from a single bad data point, using pandas.rolling.mean()

SWPC obseleted their source of recent data. As a result, we have to get Ap and f10.7 from two discrete web sources. This was a long-term pain point that has been resolved in this release.
Part of the release also needs Python >= 3.7 to make this package reliable across Python install mechanisms, including venv and non-CPython installs.

* BUG: fix Kp to have proper scaling
* move CI to github actions
* always do "install" tests