Kill zombie VMs

[bryan-brancotte]

Hello

Regarding deployment https://nuv.la/run/d909dd00-6354-4158-8fde-4e678de58390, I cancelled it, probably before the VM was actually started. That VM was not killed, and we just found out that it was alive two weeks later. Could you ensure that VMs of canceled deployments are actually stopped. Following a discution with @loomis in Barcelona it seems that it should be done by slipstream directly.

Best regards