Allow empty strings to pass validation - turn them to None when mapping to job.
Allow empty strings to pass validation - turn them to None when mapping to job.

mlhenderson/narrative,psnovichkov/narrative,pranjan77/narrative,msneddon/narrative,kbase/narrative,msneddon/narrative,briehl/narrative,pranjan77/narrative,pranjan77/narrative,jmchandonia/narrative,mlhenderson/narrative,pranjan77/narrative,pranjan77/narrative,jmchandonia/narrative,msneddon/narrative,briehl/narrative,briehl/narrative,mlhenderson/narrative,kbase/narrative,psnovichkov/narrative,psnovichkov/narrative,kbase/narrative,pranjan77/narrative,jmchandonia/narrative,psnovichkov/narrative,jmchandonia/narrative,msneddon/narrative,msneddon/narrative,kbase/narrative,mlhenderson/narrative,kbase/narrative,kbase/narrative,briehl/narrative,jmchandonia/narrative,msneddon/narrative,psnovichkov/narrative,mlhenderson/narrative,jmchandonia/narrative,briehl/narrative,briehl/narrative,briehl/narrative,jmchandonia/narrative,pranjan77/narrative,mlhenderson/narrative,psnovichkov/narrative,msneddon/narrative,psnovichkov/narrative