Check or update service dates

[adamboche]

unitedstates/congress-legislators#756 says some legislators' service dates should be changed.

[aaronrudkin]

We don't actually use legislator service dates at all. They're not in the DB. So all we have to go on are the dates during which the person voted + the born and died years. I think it would be useful to add dates of service to the DB. I also think it'd be useful to do a full re-scrape of bioguide stuff for all the previous congresses to catch updates we missed with past scrapes.

This also speaks to voteview/voteview_ingestion#86 which has no answer in the current DB.