⬆️ Update django-storages requirement

Updates the requirements on [django-storages](https://github.com/jschneier/django-storages) to permit the latest version.
- [Changelog](https://github.com/jschneier/django-storages/blob/master/CHANGELOG.rst)
- [Commits](https://github.com/jschneier/django-storages/commits)

---
updated-dependencies:
- dependency-name: django-storages
  dependency-type: direct:production
...

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

requirements.txt

@@ -76,7 +76,7 @@ django-debug-toolbar==4.2.0
 django-markwhat==1.6.2
 django-appconf==1.0.4
 django-compressor>=3.1,<5.0
-django-storages>=1.8,<1.9
+django-storages>=1.8,<1.15
 django-cacheds3storage==0.3.0
 django-impersonate==1.9.1
 django-waffle==4.0.0