Add OCDFields to provide some default fields arrays to pass to methods
Add tests for the OCDFields enumerator. Reorganize tests, putting endpoint tests toward the bottom.
Fix bill fields name. Update test for bill lookup (currently failing on upstream issue). Also add a couple of person object tests.
Add testSwiftyDivisionGeoSearch test.
Refactor tests into multiple files and classes. Most of the action is in OCDKitEndpointTests