Create the voters table

**Body:**
**User Story**

* As a user, I can request a list of voters alphabetized by last name.

* As a user, I can request a single voter's information.

* As a user, I can create a voter.

* As a user, I can update a voter's email.

* As a user, I can delete a voter.

The issue names no files, tests, or entry points, so first inspect the repository's database setup and existing voter-related code. Done means a voters table supports listing voters alphabetically by last name, retrieving one voter, creating a voter, updating an email, and deleting a voter.

Written by the indexing model from the issue text.