Django security releases issued: 2.1.5, 2.0.10, and 1.11.18

[Tim Graham]

Today the Django team issued 2.1.5, 2.0.10, and 1.11.18 as part of our security process. These releases address a security issue, and we encourage all users to upgrade as soon as possible: 

https://www.djangoproject.com/weblog/2019/jan/04/security-releases/

The issue was publicly reported through a GitHub pull request, therefore we fixed the issue as soon as possible without the usual prenotification process (https://docs.djangoproject.com/en/dev/internals/security/#how-django-discloses-security-issues).

As a reminder, we ask that potential security issues be reported via private email to secu...@djangoproject.com and not via Django's Trac  instance, Django's GitHub repositories, or the django-developers list. Please see https://www.djangoproject.com/security for further information.