Fixed broken edit handlers test

wagtail/wagtailadmin/tests/test_edit_handlers.py

@@ -343,11 +343,27 @@ class TestInlinePanel(TestCase):
             fake_page = self.FakePage()
             self.barbecue = fake_page
 
+    class FakePanel(object):
+        name = 'mock panel'
+
+        class FakeChild(object):
+            def render_js(self):
+                return "rendered js"
+
+            def rendered_fields(self):
+                return ["rendered fields"]
+
+        def init(*args, **kwargs):
+            pass
+
+        def __call__(self, *args, **kwargs):
+            fake_child = self.FakeChild()
+            return fake_child
+
     def setUp(self):
         self.fake_field = self.FakeField()
         self.fake_instance = self.FakeInstance()
-        self.mock_panel = MagicMock()
-        self.mock_panel.name = 'mock panel'
+        self.mock_panel = self.FakePanel()
         self.mock_model = MagicMock()
         self.mock_model.formset.related.model.panels = [self.mock_panel]