Update django-storages to 1.5.2

[pyup-bot]

There's a new version of django-storages available.
You are currently using 1.5.1. I have updated it to 1.5.2

These links might come in handy: PyPI | Changelog | Repo

Changelog

1.5.2

---

• Actually use SFTP_STORAGE_HOST in SFTPStorage backend (204_ thanks jbittel)
• Fix S3Boto3Storage to avoid race conditions in a multi-threaded WSGI environment (238_ thanks jdufresne)
• Fix trying to localize a naive datetime when settings.USE_TZ is False in S3Boto3Storage.modified_time.
  (thanks to tomchuk and piglei for the reports and the patches, 235, 234)
• Fix automatic bucket creation in S3Boto3Storage when AWS_AUTO_CREATE_BUCKET is True (196_ thanks linuxlewis)
• Improve the documentation for the S3 backends (thanks to various contributors!)

.. _204: jschneier/django-storages#204
.. _238: jschneier/django-storages#238
.. _234: jschneier/django-storages#234
.. _235: jschneier/django-storages#235
.. _196: jschneier/django-storages#196

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖

[mention-bot]

@pyup-bot, thanks for your PR! By analyzing the history of the files in this pull request, we identified @ad-m to be a potential reviewer.

[pyup-bot]

Closing this in favor of #107