Added conditional guards to ensure SNOPT is enabled prior to running the comparePriusURDFtoSDF unit test.
Added conditional guards to ensure SNOPT is enabled prior to running the comparePriusURDFtoSDF unit test.

sheim/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake,billhoffman/drake,billhoffman/drake