Creates the table WardrikStore.Ecto keeps keys in. Call it from a migration of your own:

defmodule MyApp.Repo.Migrations.AddWardrikStore do
  use Ecto.Migration

  def up, do: WardrikStore.Ecto.Migration.up(version: 1)
  def down, do: WardrikStore.Ecto.Migration.down(version: 1)
end

Each version is one change to the table. When a release adds a version, add a migration that runs it.