Schema Version and Migrations

[will-clark]

We need a process to version our schema and handle migrations. This could be as simple as a schema.sql file in the src directory and we "just know" when we need to deploy a schema change or we integrate with a tool like Flyway to help us do this.

[will-clark]

Flyway will run at application startup and automatically apply any new migrations.

migrations are now kept in "db/migrations".