Add Controller.apply_dependents/1

[coryodaniel]

This would be an abstraction over K8s.Client.run/N or K8s.Client.async/N.

This could be helpful with #49 #88

A function that will take a list of k8s resource definitions and creates them all.

The term here apply being borrowed from kubectl. It would add or modify resources.

def added(my_crd_added_event = %{}) do
  deployment = ...
  service = ...
  config_map = ...
  dependents = [deployment, service, config_map]

  case apply_dependents(my_crd_added_event, dependents) do
    {:ok, resources} -> IO.puts "Yay"
    {:error, resources_and_errors} -> IO.puts "boo"
  end
end

TBD: Should this operate on HTTP response or poll for k8s resource status.