Add Django version to report header

[joshuadavidthomas]

When pytest is run, it displays all the versions of the platform and plugins in the report header. Currently the pytest-django report header only adds the Django settings and (if found) configuration from django-configuration. It would be very useful if pytest-django also included the version of Django.

I recently had to debug an issue where I was swapping between two versions of Django and, while it is a small thing, having this info when running the tests would have been a nice DX improvement.

This should be an easy patch to write. Opening this issue to gauge interest.

(I searched the issues for a similar request, but did not find any. Apologies if this has been brought up before.)

[bluetech]

I think it would be nice!

[joshuadavidthomas]

🎉