BUG: batch_processing.sh: add checking if git is installed (Fix #222)
BUG: batch_processing.sh: add checking if git is installed (Fix #222)

Former-commit-id: 1dad849b0f3af01837705188d54f61272bdba55f
Former-commit-id: 692bada7b150b80069090c67857fc3da4fe67705
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox