Fixed #26013 -- Moved django.core.urlresolvers to django.urls.

Thanks to Tim Graham for the review.

tests/urlpatterns_reverse/tests.py

@@ -13,10 +13,6 @@ from django.conf import settings
 from django.conf.urls import include, url
 from django.contrib.auth.models import User
 from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
-from django.core.urlresolvers import (
-    NoReverseMatch, RegexURLPattern, RegexURLResolver, Resolver404,
-    ResolverMatch, get_callable, get_resolver, resolve, reverse, reverse_lazy,
-)
 from django.http import (
     HttpRequest, HttpResponsePermanentRedirect, HttpResponseRedirect,
 )
@@ -25,6 +21,10 @@ from django.test import (
     SimpleTestCase, TestCase, ignore_warnings, override_settings,
 )
 from django.test.utils import override_script_prefix
+from django.urls import (
+    NoReverseMatch, RegexURLPattern, RegexURLResolver, Resolver404,
+    ResolverMatch, get_callable, get_resolver, resolve, reverse, reverse_lazy,
+)
 from django.utils import six
 from django.utils.deprecation import RemovedInDjango20Warning
 
@@ -458,7 +458,7 @@ class ReverseLazySettingsTest(AdminScriptTestCase):
     """
     def setUp(self):
         self.write_settings('settings.py', extra="""
-from django.core.urlresolvers import reverse_lazy
+from django.urls import reverse_lazy
 LOGIN_URL = reverse_lazy('login')""")
 
     def tearDown(self):