Show error when saving task

attract/static/js/tasks.js

@@ -19,6 +19,7 @@ function save_task(task_id, task_url) {
         .fail(function(xhr_or_response_data) {
             // jQuery sends the response data (if JSON), or an XHR object (if not JSON).
             if (console) console.log('Failed saving', xhr_or_response_data);
+            $('#task-details').html(xhr_or_response_data.responseText);
         })
         .always(function() {
             $button.attr('disabled', false);