Log significant info using Python logging module

[DavidLemayian]

We would like to log significant events using Python's logging module and eventually send specific notifications to Slack. For our purposes we want to log:

1. When the doc_type isn't understood so that:
   • Dev team can add keyword if it is appropriate.
   • Could be a question instead or a tip-off for newsroom to follow up with.
2. When an error occurs e.g ElasticSearch is down or the nurses website is down.