Simulated Provider

A simulated implementation of a "cloud provider". In reality, a `provider` maintains some number of `datacenter`s, each of which may contain some number of `zones`, each of which contains some number of `machines` (physical and virtual).

A `client` of a `provider` may make the following requests of the provider:

machines
  create (machineDescription/s)
  destroy(machineID/s)
  status (machineID/s)
  list


Provider Data Structures

Machine
  specs

DeployedMachine : Machine
  id
  location
  status


// May be able to adapt this to a shorter, more flexible structure.
// Why these names? Why this depth?
MachineGroup : Set<Machine>

MachineZone : Set<MachineGroup>

DataCenter : Set<MachineZone>

Provider : Set<DataCenter>