Setuptools v54.1.0 introduces a warning that the use of dash-separated
options in 'setup.cfg' will not be supported in a future version [1].
Get ahead of the issue by replacing the dashes with underscores. Without
this, we see 'UserWarning' messages like the following on new enough
versions of setuptools:
UserWarning: Usage of dash-separated 'description-file' will not be
supported in future versions. Please use the underscore name
'description_file' instead
[1] https://github.com/pypa/setuptools/commit/a2e9ae4cb
Change-Id: Iabad24aab27d651aee33afbc03007cb47b47a320
* Switch to using sphinx-build
* Remove unused requirements.txt file
* Remove cruft from setup.cfg and doc/source/conf.py
* Switch to Python3
Change-Id: I5f50c345a3fc5cdb58221541f0186990d22ffd5d