Automated tests for external data sources using real data

[sdn90]

We can replace the test fixtures for contact-congress and congress-legislators with the actual data used since it does not that that often. We can also run it on a schedule to test any updates from those data sources.

https://docs.travis-ci.com/user/cron-jobs/
(see if we can auto open PR's whenever the scheduled test fails)

congress-legislators

• Test all possible district and state combinations, make sure all legislators are findable

contact-congress

• On the front end, test that all legislator's $TOPIC field values can be rendered