MachineDeployment
A MachineDeployment orchestrates deployments over a fleet of MachineSets.
Its main responsibilities are:
- Adopting matching MachineSets not assigned to a MachineDeployment
 - Adopting matching MachineSets not assigned to a Cluster
 - Managing the Machine deployment process
- Scaling up new MachineSets when changes are made
 - Scaling down old MachineSets when newer MachineSets replace them
 
 - Updating the status of MachineDeployment objects
 
