remove records that have dim SN This was set correctly for sedFilepath but we need to do this for   shortFileNames - make shorterFileNames a `numpy.array` so that a dtype exists - if shortFileNames includes 'None', set the spectral file name to 'None'     otherwise return the shorterFileName - rewrite `cannot_be_null` to reject None records. - checked that the seddir variable is not used but that the spectra are   indeed printed to the right location 	modified:   twinklesCatalogDefs.py
remove records that have dim SN
This was set correctly for sedFilepath but we need to do this for
  shortFileNames
- make shorterFileNames a `numpy.array` so that a dtype exists
- if shortFileNames includes 'None', set the spectral file name to 'None'
    otherwise return the shorterFileName
- rewrite `cannot_be_null` to reject None records.
- checked that the seddir variable is not used but that the spectra are
  indeed printed to the right location
	modified:   twinklesCatalogDefs.py

LSSTDESC/Twinkles,DarkEnergyScienceCollaboration/Twinkles,DarkEnergyScienceCollaboration/Twinkles,LSSTDESC/Twinkles