fix utcoffset, dst issue in test_solpos
fix utcoffset, dst issue in test_solpos

* if dst is zero then dt.dst() or 0.0 return 0.0 since timedelta(0) is False
* float, ie: 0.0, has no total_seconds() method
* don't do this or that, just get utcoffset and dst, then if either are None set tz=0

SunPower/UncertaintyWrapper