Fix ValueError in environment details page

Deploy an environment 'foo', then go the Environments->foo->Deployment
History->Show Details. Horizon throws the error 'ValueError: Need 2
values to unpack in for loop; got 1.' Same fix that was provided for bug
1703197 applies here.

Change-Id: I09bac0f2d5197482cf8bc034099a2afeb5db82c2
Closes-Bug: #1724571

muranodashboard/environments/views.py

@@ -230,7 +230,7 @@ class DeploymentDetailsView(tabs.TabbedTableView):
             (context["environment_name"],
              reverse("horizon:app-catalog:environments:services",
                      args=[self.environment_id])),
-            (_('Deployments'),), ]
+            (_('Deployments'), None)]
         context["custom_breadcrumb"] = breadcrumb
         return context
 

muranodashboard/tests/unit/environments/test_views.py

@@ -343,7 +343,7 @@ class TestDeploymentDetailsView(testtools.TestCase):
             'deployment_start_time': 'foo_deployment_start',
             'custom_breadcrumb': [
                 ('foo_env_name', 'foo_reverse_url'),
-                (_('Deployments'),),
+                (_('Deployments'), None)
             ]
         }