An ocurrent plugin to deploy MirageOS unikernels

This is an ocurrent plugin to manage deployment of unikernels. It's specialized for linux, using Albatross for orchestrating the virtual machines and iptables for exposing ports.

It's been made with zero downtime in mind, meaning that when an unikernel is updated, a new instance is started while keeping the old one alive, and the switch to the new instance is managed using a port redirection to the new IP.