Add tests and changelog to sdist

[jayvdb]

No description provided.

[adamchainz]

I recommend not distributing the tests. 99.99% of installs do not need them. Those who want them are normally redistributors, can who fetch the tarball from the repo. Last year I removed tests from the sdists in all my projects and heard no complaints.

Is redistributing your motivation here @jayvdb ? Have you considered using repo tarballs?

[jayvdb]

https://pypi.org/project/daphne/#files includes wheels, which is what 99% of installs will fetch.
The sdist is for the other 1% need.

Yes, https://build.opensuse.org/package/show/devel:languages:python:django/python-django-cors-headers and https://build.opensuse.org/package/show/devel:languages:python:django/python-django-upgrade were broken when tests were removed, which is why they have not been updated , because the automated update system only works when fetching from pypi.

Using tarballs from github is more effort, which I will do because these are important packages and they are already in the openSUSE collection. Before adding new packages to openSUSE, and thus more work, I try to have the sdists on PyPI include tests, as I did in adamchainz/django-cors-headers#378 .