Create a function createRolesTable to create a Roles table: roles

[jaytula]

We'll need a roles table if we're going to have users with different permissions.

The roles table should have two fields:

• rid for role id
• name for the role name

This should be similar to the createUsersTable and it should also be run in db-setup.ts. Some things to note:

• Currently quiz_db.sql sets up all the tables and is setup to run once when used with the docker-compose.yml setup. We could choose to maintain this and re-create this SQL dump but existing docker containers won't update themselves. Therefore running npm run db-setup is necessary if the database schema expectation changes.
• Probably best to create the function in db/roles.ts
• Create tests to check proper creation of table in tests/roles.test.ts. See users.test.ts.
  • Handle the case for when the table already exists