model/migration for promoted statuses

db/migrate/20190903162122_create_promotions.rb

@@ -0,0 +1,11 @@
+class CreatePromotions < ActiveRecord::Migration[5.2]
+  def change
+    create_table :promotions do |t|
+      t.timestamps
+      t.datetime :expires_at, null: true
+      t.bigint :status_id, null: false
+      t.string :timeline_id, null: true
+      t.integer :position, default: 10
+    end
+  end
+end