Macro that generates a Migrator for a plugin.
Each plugin defines:
defmodule VoileLockerLuggage.Migrator do
use Voile.Plugin.Migrator, otp_app: :voile_locker_luggage
endThe otp_app option tells the migrator where to find
priv/migrations/ for this plugin's OTP application.
Generates run/0, rollback/0, migrated?/0, and status/0.