Migration adding backup mode to user export

db/migrate/20180130174500_add_backup_to_user_migration_exports.rb

@@ -0,0 +1,12 @@
+require 'carto/db/migration_helper'
+
+include Carto::Db::MigrationHelper
+
+migration(
+  Proc.new do
+    add_column :user_migration_exports, :backup, :boolean, default: false, null: false
+  end,
+  Proc.new do
+    drop_column :user_migration_exports, :backup
+  end
+)