cmd/kola: add spawn subcommand
cmd/kola: add spawn subcommand

mjg59/mantle,mischief/mantle,mischief/mantle,dm0-/mantle,marineam/mantle,marineam/mantle,glevand/coreos--mantle,glevand/coreos--mantle,quantum/coreos-mantle,dm0-/mantle,mjg59/mantle,quantum/coreos-mantle