another sql mutation bites the dust.

src/clj/auto_ap/graphql.clj

@@ -324,7 +324,7 @@
                    :args {:invoice {:type :edit_invoice}}
                    :resolve :mutation/edit-invoice}
     :void_invoice {:type :invoice
-                   :args {:invoice_id {:type 'Int}}
+                   :args {:invoice_id {:type 'String}}
                    :resolve :mutation/void-invoice}
     :void_payment {:type :payment
                  :args {:payment_id {:type 'String}}