GeneralStepUiTest: Fix failing test case in newer version of Node

An error was being thrown outside the stack of the actual test, which
apparently was never noticed until more recent versions of node.  We're
still on a pretty ancient version for local development. :x

* test/ui/step/GeneralStepUiTest.js (createElementStyler)[getAnswerElementByName]:
  Properly return array for stub jQuery element.

test/ui/step/GeneralStepUiTest.js

@@ -329,12 +329,14 @@ function createElementStyler( style_callback )
         getAnswerElementByName: function()
         {
             // jQuery element
-            return {
+            const $element = [ {
                 attributes: [],
-                length:     1,
+            } ];
 
-                text: function() {},
-            }
+            $element.length = 1;
+            $element.text   = () => {};
+
+            return $element;
         },
 
         getProperIndex: function()