fluor_fvfm_bad_input_test
fluor_fvfm_bad_input_test

added a bad input test to cover the fatal error in the fluor_fvfm function

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