MVP

@ibuildthecloud 
I believe this is exactly what Args() will do for you.  I did a similar thing in https://github.com/ibuildthecloud/systemd-docker.  With `rancher --url http://... container create --name abc`, Args() should become `[]string{"container", "create", "--name", "abc"}`  Please test, I could be wrong, but I believe the flags parser stops on the first non-flag and treats the rest as arguments, not flags.