Dj-email-url

- Removed support for Python versions which reached end-of-life.

- Fixed typo. Thanks to jeffmacdonald.

- Added support for ``DEFAULT_FROM_EMAIL`` and ``SERVER_EMAIL`` in the URL as
query parameters.

- Added new schemes ``submission`` and ``submit``
to select SMTP backend on port 587 with STARTTLS.
Thanks to LEW21 to suggest to include new `submit` URI.

- Discouraged the use of scheme ``smtps`` and add a user warning.
Thanks to LEW21 to alert about this confusing usage.

- Expand which values are considered as truthy on a query string param. Now,
`1`, `on`, `true`, and `yes`, as a single character or in all case variants
(lower, upper and title case) are considered as `True`.