Makefile fix to rm pod-build on clean.
Makefile fix to rm pod-build on clean.

thientu/drake,sheim/drake,sheim/drake,tkoolen/drake,thientu/drake,edowson/drake,psiorx/drake,astrorog/drake,crogers3/drake,edowson/drake,tkoolen/drake,hanssusilo/drake,sheim/drake,psiorx/drake,crogers3/drake,crogers3/drake,tkoolen/drake,manuelli/drake,scottviteri/drake,tkoolen/drake,astrorog/drake,hanssusilo/drake,sheim/drake,manuelli/drake,edowson/drake,psiorx/drake,astrorog/drake,sheim/drake,thientu/drake,scottviteri/drake,thientu/drake,thientu/drake,sheim/drake,hanssusilo/drake,thientu/drake,sheim/drake,edowson/drake,billhoffman/drake,hanssusilo/drake,tkoolen/drake,psiorx/drake,edowson/drake,billhoffman/drake,hanssusilo/drake,scottviteri/drake,tkoolen/drake,edowson/drake,manuelli/drake,crogers3/drake,billhoffman/drake,manuelli/drake,crogers3/drake,billhoffman/drake,psiorx/drake,billhoffman/drake,billhoffman/drake,thientu/drake,crogers3/drake,hanssusilo/drake,crogers3/drake,scottviteri/drake,astrorog/drake,scottviteri/drake,hanssusilo/drake,manuelli/drake,manuelli/drake,scottviteri/drake,scottviteri/drake,edowson/drake,edowson/drake,hanssusilo/drake,astrorog/drake,psiorx/drake,psiorx/drake,crogers3/drake,manuelli/drake,billhoffman/drake,tkoolen/drake,sheim/drake,astrorog/drake,billhoffman/drake,astrorog/drake,psiorx/drake