Update django-debug-toolbar to 1.11

[pyup-bot]

This PR updates django-debug-toolbar from 1.10.1 to 1.11.

Changelog

1.11

-----------------

* Use ``defer`` on all ``<script>`` tags to avoid blocking HTML parsing,
removed inline JavaScript.
* Stop inlining images in CSS to avoid Content Security Policy errors
altogether.
* Reformatted the code using `black <https://github.com/ambv/black>`__.
* Added the Django mail panel to the list of third-party panels.
* Convert system check errors to warnings to accomodate exotic
configurations.
* Fixed a crash when explaining raw querysets.
* Fixed an obscure unicode error with binary data fields.
* Added MariaDB and Python 3.7 builds to the CI.

Links

• PyPI: https://pypi.org/project/django-debug-toolbar
• Changelog: https://pyup.io/changelogs/django-debug-toolbar/
• Repo: https://github.com/jazzband/django-debug-toolbar