update analyze_spectral
update analyze_spectral

There are specific datatypes that are allowed with writing a dictionary from the Outputs observations class to a json text file. Converting to string was useful for avoiding float32 but we don't want wavelengths or reflectance frequencies to be strings so instead update the datatype transformation steps.

stiphyMT/plantcv,danforthcenter/plantcv,stiphyMT/plantcv,stiphyMT/plantcv,danforthcenter/plantcv,danforthcenter/plantcv