update datatype in dictionary
update datatype in dictionary

Update the dictionary created from the metadata in the .hdr file to replace the ID number for datatype with the actual numpy datatype.

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