Merged in kidmose/pywhois/feature/test-missing-keys (pull request #33)
test_parser.py: Fail on missing keys
{"domain_name": "nyan.cat", "expiration_date": "2018-04-13 19:52:17.635000", "updated_date": "2017-07-07 17:24:23.746000", "creation_date": "2011-04-13 19:52:17.635000", "status": "ok https://icann.org/epp#ok"}