Consider switching endpoints to FullDate

[cnlucas]

We moved calendar-dates and calendar-dates/export to FullDate. Once those are in production and tested further--should we consider moving other endpoints to FullDate and removing Date?

We should update the swagger for min and max election_dates to add date formats. As a team, we should also decide if we'd like to add ISO8601 formats to swagger.

• min and max election dates swagger updates
• change hits_returned to max 200 in the example see here