Jormungandr: add a scenario for destineo

min_nb_journeys is used for finding journeys without alternative mode
like bike, after having found N journeys with walking and TC, we search
alternative solution with bike, bss and car
Scenario destineo: remove car journey if possible

If there is others solutions with alternative fallback mode we remove the
car solution.
Merge pull request #678 from kinnou02/scenario_destineo

Jormungandr: add a scenario for destineo