Update django-extra-views requirement from ==0.11.* to ==0.12.*

Updates the requirements on [django-extra-views](https://github.com/AndrewIngram/django-extra-views) to permit the latest version.
- [Release notes](https://github.com/AndrewIngram/django-extra-views/releases)
- [Changelog](https://github.com/AndrewIngram/django-extra-views/blob/master/CHANGELOG.rst)
- [Commits](AndrewIngram/django-extra-views@0.11.0...0.12.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements/base.txt

@@ -1,3 +1,3 @@
 setuptools
-django-extra-views==0.11.*
+django-extra-views==0.12.*
 django-betterforms==1.1.*