Update django-debug-toolbar to 3.1

[pyup-bot]

This PR updates django-debug-toolbar from 2.1 to 3.1.

Changelog

3.1

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

* Fixed a crash in the history panel when sending an empty JSON POST
request.
* Made ``make example`` also set up the database and a superuser
account.
* Added a Makefile target for regenerating the django-debug-toolbar
screenshot.
* Added automatic escaping of panel titles resp. disallowed HTML tags.
* Removed some CSS
* Restructured the SQL stats template.
* Changed command line examples to prefer ``python -m pip`` to ``pip``.

3.0

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

* Added an ``.editorconfig`` file specifying indentation rules etc.
* Updated the italian translation.
* Added support for Django 3.1a1. ``fetch()`` and ``jQuery.ajax`` requests are
now detected by the absence of a ``Accept: text/html`` header instead of the
jQuery-specific ``X-Requested-With`` header on Django 3.1 or better.
* Pruned unused CSS and removed hacks for ancient browsers.
* Added the new :attr:`Panel.scripts <debug_toolbar.panels.Panel.scripts>`
property. This property should return a list of JavaScript resources to be
loaded in the browser when displaying the panel. Right now, this is used by a
single panel, the Timer panel. Third party panels can use this property to
add scripts rather then embedding them in the content HTML.
* Switched from JSHint to ESLint. Added an ESLint job to the Travis CI matrix.
* Debug toolbar state which is only needed in the JavaScript code now uses
localStorage.
* Updated the code to avoid a few deprecation warnings and resource warnings.
* Started loading JavaScript as ES6 modules.
* Added support for ``cache.touch()`` when using django-debug-toolbar.
* Eliminated more inline CSS.
* Updated ``tox.ini`` and ``Makefile`` to use isort>=5.
* Increased RESULTS_CACHE_SIZE to 25 to better support AJAX requests.
* Fixed the close button CSS by explicitly specifying the
``box-sizing`` property.
* Simplified the ``isort`` configuration by taking advantage of isort's
``black`` profile.
* Added HistoryPanel including support for AJAX requests.

**Backwards incompatible changes**
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

* Loading panel content no longer executes the scripts elements embedded in the
HTML. Third party panels that require JavaScript resources should now use the
:attr:`Panel.scripts <debug_toolbar.panels.Panel.scripts>` property.
* Removed support for end of life Django 1.11. The minimum supported Django is
now 2.2.

2.2

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

* Removed support for end of life Django 2.0 and 2.1.
* Added support for Python 3.8.
* Add locals() option for sql panel.
* Added support for Django 3.0.

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

[coveralls]

Coverage remained the same at 96.958% when pulling 9bb328a on pyup-update-django-debug-toolbar-2.1-to-3.1 into a9b3e81 on master.

[pyup-bot]

Closing this in favor of #389