"CHANGELOG.rst" did not exist on "a9cc479a1506bd5f4a6aa9d9fc7ec0f487f27f3e"
setup.py: Force Sphinx > 2 for readthedocs
FIX
readthedocs uses an old version of sphinx for projects created before 2020: https://github.com/mgeier/sphinx-last-updated-by-git/issues/1
So force a newer version.