Log Message:
Updated py-ZopeInterface to 4.4.2.

4.4.2 (2017-06-14)
------------------

- Fix a regression storing
  ``zope.component.persistentregistry.PersistentRegistry`` instances.
  See `issue 85 <https://github.com/zopefoundation/zope.interface/issues/85>`_.

- Fix a regression that could lead to the utility registration cache
  of ``Components`` getting out of sync. See `issue 93
  <https://github.com/zopefoundation/zope.interface/issues/93>`_.