Download immunization records from AISR

[DillonOLeary]

Hopefully with everything else set up this should be easier. For this, we need to use the existing Selenium script to download processed files from schools. I'm not sure if all files show up, or if just the csvs requested by the user. I think in either case, we should just grab the latest. In the future, we can add an option to grab a stale file, but I don't see any use case for this.

AC

• should be able to download a csv from AISR using the command line and the extract argument
• unit tests should cover this behavior
• integration tests should also cover this behavior