Merge pull request #15532 from…

Merge pull request #15532 from edx/mroytman/PLAT_1487_django_1.11_upgrade_edx-django-sites-extensions

upgrade edx-django-sites-extensions from 2.1.1 to 2.3.0

requirements/edx/base.txt

@@ -52,7 +52,7 @@ edx-lint==0.4.3
 # when upgrading edx-lint, we should try to remove this from the platform
 astroid==1.3.8
 edx-django-oauth2-provider==1.1.4
-edx-django-sites-extensions==2.1.1
+edx-django-sites-extensions==2.3.0
 edx-enterprise==0.36.5
 edx-oauth2-provider==1.2.0
 edx-opaque-keys==0.4.0