TEST: updated travis script to test the toolbox installer and package creation
TEST: updated travis script to test the toolbox installer and package creation

Former-commit-id: a42eeb2666268b33e833ce9fcbc58a7951524170
Former-commit-id: 666e96d94923849adbb4de0648debd52f893fdb4
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox