Django 2.0 support

Replace django.core.urlresolves with django.urls

(In Django 2.0) The django.core.urlresolvers module is removed
in favor of its new location, django.urls.
It was depreacted in Django 1.10:
https://docs.djangoproject.com/en/2.0/releases/1.10/#id3

Add py35dj20 job to test Django 2.0 integration.
Also drops py27dj110 from tox.ini as horizon droped
Django 1.10 support in Rocky.

blueprint django2-support

Change-Id: I8e0dcb64e1c82580767db482631450ba38654fc3

.zuul.yaml

@@ -4,8 +4,14 @@
         - openstack-tox-lower-constraints:
             required-projects:
               - openstack/horizon
+        - horizon-openstack-tox-py35dj20:
+            required-projects:
+              - openstack/horizon
     gate:
       jobs:
         - openstack-tox-lower-constraints:
             required-projects:
               - openstack/horizon
+        - horizon-openstack-tox-py35dj20:
+            required-projects:
+              - openstack/horizon

neutron_fwaas_dashboard/dashboards/project/firewalls/forms.py

@@ -14,7 +14,7 @@
 
 import logging
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 
 from horizon import exceptions

neutron_fwaas_dashboard/dashboards/project/firewalls/tables.py

@@ -14,8 +14,8 @@
 
 import logging
 
-from django.core.urlresolvers import reverse
 from django.template import defaultfilters as filters
+from django.urls import reverse
 from django.utils.translation import pgettext_lazy
 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ungettext_lazy

neutron_fwaas_dashboard/dashboards/project/firewalls/tests.py

@@ -14,7 +14,7 @@
 
 import mock
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 
 from openstack_dashboard import api
 from openstack_dashboard.test import helpers

neutron_fwaas_dashboard/dashboards/project/firewalls/views.py

@@ -12,8 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from horizon import exceptions

neutron_fwaas_dashboard/dashboards/project/firewalls_v2/forms.py

@@ -15,7 +15,7 @@
 import logging
 from operator import attrgetter
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 from django.utils.translation import ugettext_lazy as _
 from horizon import exceptions
 from horizon import forms

neutron_fwaas_dashboard/dashboards/project/firewalls_v2/tables.py

@@ -14,8 +14,8 @@
 
 import logging
 
-from django.core.urlresolvers import reverse
 from django.template import defaultfilters as filters
+from django.urls import reverse
 from django.utils.translation import pgettext_lazy
 from django.utils.translation import ugettext_lazy as _
 from django.utils.translation import ungettext_lazy

neutron_fwaas_dashboard/dashboards/project/firewalls_v2/tests.py

@@ -12,7 +12,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from django.core.urlresolvers import reverse
+from django.urls import reverse
 import mock
 
 from openstack_dashboard.test import helpers

neutron_fwaas_dashboard/dashboards/project/firewalls_v2/views.py

@@ -12,8 +12,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from django.core.urlresolvers import reverse
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse
+from django.urls import reverse_lazy
 from django.utils.translation import ugettext_lazy as _
 
 from horizon import exceptions

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py35,py27,pep8
+envlist = py35,py27,pep8,py35dj20
 minversion = 2.3.2
 skipsdist = True
 
@@ -35,10 +35,10 @@ commands =
   coverage xml --omit '.tox/cover/*' -o 'cover/coverage.xml'
   coverage html --omit '.tox/cover/*' -d 'cover/htmlcov'
 
-[testenv:py27dj110]
-basepython = python2.7
+[testenv:py35dj20]
+basepython = python3.5
 commands =
-  pip install django>=1.10,<1.11
+  pip install django>=2.0,<2.1
   {[unit_tests]commands}
 
 [testenv:docs]