Addresses ERROR:  date/time field value out of range in PostgreSQL unit test

ActiveRecord::StatementInvalid: PG::DatetimeFieldOverflow: ERROR:  date/time field value out of range: "0000-01-01 04:56:01.000000 BC"
: INSERT INTO "developers" ("created_at", "created_on", "name", "updated_at", "updated_on") VALUES ($1, $2, $3, $4, $5) RETURNING "id"