fix up error handling / checking for osm and osmosis
fix up error handling / checking for osm and osmosis

LACMTA/loader,OpenTransitTools/loader,OpenTransitTools/loader,OpenTransitTools/loader,LACMTA/loader,OpenTransitTools/deploy,LACMTA/loader,LACMTA/loader,OpenTransitTools/loader,OpenTransitTools/deploy,LACMTA/loader,OpenTransitTools/loader