[Security] Bump Django to 3.0.1

[phacks]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting)
• Refactoring (no functional changes)
• Documentation content changes

Other information

This bump fixes CVE-2019-19844:

Django's password-reset form uses a case-insensitive query to retrieve accounts matching the email address requesting the password reset. Because this typically involves explicit or implicit case transformations, an attacker who knows the email address associated with a user account can craft an email address which is distinct from the address associated with that account, but which -- due to the behavior of Unicode case transformations -- ceases to be distinct after case transformation, or which will otherwise compare equal given database case-transformation or collation behavior. In such a situation, the attacker can receive a valid password-reset token for the user account.

Source: https://www.djangoproject.com/weblog/2019/dec/18/security-releases/