breaks method using only scalars for nobs > 1

[mikofski]

if wrapped method has scalar args and is called with multiple observations, uncwrapper will expand that scalar into a ndarray same size as nobs on L62 of partial_derivative(). So if the wrapped method can't handle that normally scalar arg as a sequence, then uncwrapper breaks the method.

EG: SolarUtils solposAM(location, datetime, weather) likes location to have scalar (latitude, longitude, tz) only, but if weather is a list of temperatures and pressures, then uncwrapper turns lat, lon into lists too, breaking solposAM.

temporary workaround is to wrap the method and handle the scalar inputs before passing them in.