Merged in kidmose/pywhois/feature/test-missing-keys (pull request #33)
test_parser.py: Fail on missing keys
{"domain_name": "DAVIDWALSH.NAME", "expiration_date": null, "updated_date": null, "creation_date": null, "status": "clientTransferProhibited https://icann.org/epp#clientTransferProhibited"}