Handle KeyError: 'authority' issue

[sentry-io]

Sentry Issue: BOUNCER-1X

KeyError: 'authority'
(4 additional frame(s) were not displayed)
...
  File "bouncer/views.py", line 46, in annotation
    parsed_document = util.parse_document(document)
  File "bouncer/util.py", line 76, in parse_document
    authority = annotation["authority"]