Exclude test suite from source distribution

[hakonanes]

Currently, tests are included in the source distribution on PyPI (https://pypi.org/project/diffsims/#files). This way, users can run the test suite by doing

> pip install diffsims pytest
> pytest --pyargs diffsims

We may introduce a 125 kB NumPy array file in #205. This will take the distribution size from 946 kB -> 1071 kB.

I don't know, but I doubt there are many people running diffsims' test suite this way. I suggest to exclude the test suite from the source distribution. Interested to hear other's thoughts.

[CSSFrancis]

+1

[hakonanes]

I've taken a U-turn and now suggest to leave the tests in the source distribution. Even though the distribution size increases. Are you still fine with that, @CSSFrancis?

Whether this is a good idea or not is an open question. The general consensus among CPython core developers (https://discuss.python.org/t/should-sdists-include-docs-and-tests/14578/25, top hit on my internet search) seems to be that being able to run tests from the source distribution is a good idea.

[hakonanes]

For future reference, this is one way of excluding tests from the sdist:

• Add a line prune diffsims/tests to our MANIFEST.in file
• Add a line diffsims/tests/** to known_excludes in our setup.cfg file to make manifix happy

[CSSFrancis]

@hakonanes yea, that works for me!