REF: Make 'type' mandatory (use either 'im' or 'seg'). See issue #1034
REF: Make 'type' mandatory (use either 'im' or 'seg'). See issue #1034

Former-commit-id: 57414274eb7d144e518404f3b342090934b3b126
Former-commit-id: 6d52ab6ff9ec428189f3baf576e09b327bcefae1
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox