Make it reversible

db/migrate/20211011115946_rename_economic_status_fields.rb

@@ -8,7 +8,7 @@ class RenameEconomicStatusFields < ActiveRecord::Migration[6.1]
       t.rename :person_6_economic, :person_6_economic_status
       t.rename :person_7_economic, :person_7_economic_status
       t.rename :person_8_economic, :person_8_economic_status
-      t.remove :postcode
+      t.remove :postcode, :string
     end
   end
 end