Bump daphne from 2.3.0 to 2.5.0

Bumps [daphne](https://github.com/django/daphne) from 2.3.0 to 2.5.0.
- [Release notes](https://github.com/django/daphne/releases)
- [Changelog](https://github.com/django/daphne/blob/master/CHANGELOG.txt)
- [Commits](django/daphne@2.3.0...2.5.0)

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

requirements/base.txt

@@ -14,7 +14,7 @@ constantly==15.1.0
 contextvars==2.4
 coreapi==2.3.3  # https://github.com/core-api/python-client
 cryptography==2.7
-daphne==2.3.0
+daphne==2.5.0
 django==2.2.13  # https://www.djangoproject.com/
 django-allauth==0.42.0  # https://github.com/pennersr/django-allauth
 django-cors-headers==3.1.0