Fix run command's service check logic
Fix run command's service check logic

The command would panic if no service were provided, or would not allow
running a service without additional comandParts.

Signed-off-by: Dustin Chapman <2cf194b19224063acb6391da43dbe85a3608e663@gmail.com>

weitenghuang/libcompose,weitenghuang/libcompose,jainvipin/libcompose,vito-c/libcompose,dweomer/docker-libcompose,Azure22/libcompose,dweomer/docker-libcompose,docker/libcompose,vito-c/libcompose,Azure22/libcompose,docker/libcompose,vdemeester/libcompose,jainvipin/libcompose,vdemeester/libcompose