Fix failing tests: add new field display_zone_borders.

tests/unit/data/html/config_out.json

@@ -8,6 +8,7 @@
     "item_background_color": "white",
     "item_text_color": "#000080",
     "initial_feedback": "HTML <strong>Intro</strong> Feed",
+    "display_zone_borders": false,
     "display_zone_labels": false,
 
     "zones": [

tests/unit/data/old/config_out.json

@@ -8,6 +8,7 @@
     "item_background_color": null,
     "item_text_color": null,
     "initial_feedback": "Intro Feed",
+    "display_zone_borders": false,
     "display_zone_labels": false,
 
     "zones": [

tests/unit/data/plain/config_out.json

@@ -8,6 +8,7 @@
     "item_background_color": null,
     "item_text_color": null,
     "initial_feedback": "This is the initial feedback.",
+    "display_zone_borders": false,
     "display_zone_labels": false,
 
     "zones": [

tests/unit/test_basics.py

@@ -28,6 +28,7 @@ class BasicTests(TestCaseMixin, unittest.TestCase):
         zones = config.pop("zones")
         items = config.pop("items")
         self.assertEqual(config, {
+            "display_zone_borders": False,
             "display_zone_labels": False,
             "title": "Drag and Drop",
             "show_title": True,