Merge pull request #27 from ARYAN-NIKNEZHAD/bug/export-admin-invoice

fix(resource): Update dehydrate method for contacts to get from customer

sage_invoice/resource.py

@@ -292,4 +292,4 @@ def dehydrate_category(self, invoice):
 
     def dehydrate_contacts(self, invoice):
         """Export contacts JSON field."""
-        return json.dumps(invoice.contacts)
+        return json.dumps(invoice.customer.contact)