[idea] Remove nose from testing & docs

[henryiii]

I've noticed the Windows Travis build failed because it couldn't download nose - can we remove nose from our tests and docs? Nose has been abandoned since 2015 in favor of pytest, which can run nose tests (and unittest and its own pytest format too). All major packages (including NumPy) transitioned over to pytest from nose. Showing abandonware in examples is not a great idea, IMO. :)

git grep nose

.gitignore:nosetests.xml
docs/options.md:# run the project tests against the installed wheel using `nose`
docs/options.md:CIBW_TEST_COMMAND: nosetests {project}/tests
docs/options.md:CIBW_TEST_REQUIRES: nose==1.3.7 moto==0.4.31
test/test_before_test.py:        'CIBW_TEST_REQUIRES': 'nose',
test/test_before_test.py:        'CIBW_TEST_COMMAND': 'false || nosetests {project}/test',
test/test_before_test.py:        'CIBW_TEST_COMMAND_WINDOWS': 'nosetests {project}/test',
test/test_testing.py:        test = nose
test/test_testing.py:        'CIBW_TEST_REQUIRES': 'nose',
test/test_testing.py:        'CIBW_TEST_COMMAND': 'false || nosetests {project}/test',
test/test_testing.py:        'CIBW_TEST_COMMAND_WINDOWS': 'COLOR 00 || nosetests {project}/test',
test/test_testing.py:        'CIBW_TEST_COMMAND': 'false || nosetests {project}/test',
test/test_testing.py:        'CIBW_TEST_COMMAND_WINDOWS': 'COLOR 00 || nosetests {project}/test',
test/test_testing.py:            'CIBW_TEST_REQUIRES': 'nose',
test/test_testing.py:            'CIBW_TEST_COMMAND': 'nosetests {project}/test',

[joerick]

Yes, that makes sense to me. I think that originally it was nosetests in the testing tests rather than pytest so that we were sure that TEST_REQUIRES had worked. So it might be worth considering that when modernising. if we shell out to pytest something in our test, are we sure we aren't getting the host's version of pytest.

[henryiii]

Then we could add an import X, where X is something we require? Like something pure Python near the top of this list? https://pythonwheels.com/

I'm quite sure I do this somewhere with requests. Don't remember where or why, though, just remember picking a recent version of requests.