Django-admin-shell

* Add missing `bootstrap.min.css.map` file - refer to issue 8

* Support for Django 4.0 and Django 4.2
* Tests for Python 3.10
* Replaced test via tox from Python 3.6 to 3.7
* Verified support for latest webbrowsers
* Drop support for Django 1.10 and 1.11
* Drop support for Python 2.7

* Added flag `ADMIN_SHELL_CLEAR_SCOPE_ON_CLEAR_HISTORY` to
to enable the gargabe collector on the declared variables
from the shell (author: Rodrigo Castro - rodrigondec)

* Auto import of models and Django tools (like shell_plus).
More details in `README.rst` in section about `ADMIN_SHELL_IMPORT_DJANGO` and
`ADMIN_SHELL_IMPORT_MODELS` settings - refer to issue 1
* Support for Django 3.1 and Django 3.2
* Tests for Python 3.8
* Django" instead of "Djang" in titlebar - refer to issue 2
* Drop support for Django 1.9
* Remove integration with Travis

* Added MANIFEST.in - Issue 2

* Added support for python 3.6
* Added support Django 3.0
* Verified support for latest webbrowsers