REF: Make 'type' mandatory (use either 'im' or 'seg'). NOT IF STEP=0 See issue #1034
REF: Make 'type' mandatory (use either 'im' or 'seg'). NOT IF STEP=0 See issue #1034

Former-commit-id: 14fd29404a09fe1d221364c2214819b55f69e498
Former-commit-id: 09db60a52d08d279417e7f59ff323335357c71a5
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox