Validation and tests for input data

[dphiffer]

Currently we don't have many tests to verify that what we have in the database is reasonable and correct. We should add more tests to ensure that:

• We have all the Congress legislators accounted for
• Each congress legislator's data has all fields needed for scorecards
• All the endpoints return a JSON result and the right HTTP status code
• Have we retained manual edits to the data:
  • John McCain modifications
  • Brenda Jones addition
  • Chuck Schumer nickname