Test failure with python 3.9

[opoplawski]

python-numpydoc fails to build with Python 3.9.0a6.

======================================================================
FAIL: test_docscrape.test_see_also_print
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Traceback (most recent call last):
  File "/usr/lib/python3.9/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/builddir/build/BUILD/numpydoc-0.9.2/numpydoc/tests/test_docscrape.py", line 860, in test_see_also_print
    assert(':func:`func_a`, :func:`func_b`' in s)
AssertionError

----------------------------------------------------------------------
Ran 48 tests in 0.354s

FAILED (failures=1)

For the build logs, see:
https://copr-be.cloud.fedoraproject.org/results/@python/python3.9/fedora-rawhide-x86_64/01365545-python-numpydoc/

https://bugzilla.redhat.com/show_bug.cgi?id=1830971