PDBs fail to sync when switching between maxUnavailable <> minAvailable`

[wonderhoss]

When a pdb changes from maxUnavailable to minAvailable or vice versa, the update fails with

      is invalid: [spec: Invalid value: policy.PodDisruptionBudgetSpec{MinAvailable:(*intstr.IntOrString)(0xc425d44200),
      Selector:(*v1.LabelSelector)(0xc425d44220), MaxUnavailable:(*intstr.IntOrString)(0xc425d44240)}:
      minAvailable and maxUnavailable cannot be both set, spec: Forbidden: updates
      to poddisruptionbudget spec are forbidden.]'

[JoelSpeed]

I think this should be fixed now that we have implemented #77, we should add a test for this case in pkg/utils/client