INST: new installer for developers
INST: new installer for developers

Former-commit-id: b90ff5a051cea82149cc429e3bebc492418a98a7
Former-commit-id: f80a87d15fc7a96d368a627109447f0a2a588751
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox