Added missing backslash in sitemaps_tests urls.

tests/sitemaps_tests/urls/http.py

@@ -144,10 +144,10 @@ urlpatterns = [
     url(r'^lastmod-mixed/sitemap\.xml$', views.sitemap,
         {'sitemaps': fixed_lastmod__mixed_sitemaps},
         name='django.contrib.sitemaps.views.sitemap'),
-    url(r'^lastmod/date-sitemap.xml$', views.sitemap,
+    url(r'^lastmod/date-sitemap\.xml$', views.sitemap,
         {'sitemaps': {'date-sitemap': DateSiteMap}},
         name='django.contrib.sitemaps.views.sitemap'),
-    url(r'^lastmod/tz-sitemap.xml$', views.sitemap,
+    url(r'^lastmod/tz-sitemap\.xml$', views.sitemap,
         {'sitemaps': {'tz-sitemap': TimezoneSiteMap}},
         name='django.contrib.sitemaps.views.sitemap'),
     url(r'^lastmod-sitemaps/mixed-ascending.xml$', views.sitemap,