Since setuptools v54.1.0[1], the parmeters with dash have been
deprecated in favor of the new parameters with underscore.
This change updates the parameters accordingly to avoid the warnings
like the example below.
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: I8695d1b501f04a333caf080c835c6388415e52cf
Remove py35 testing, for train py35 is not supported anymore.
Update docs environment to use sphinx-build directly following PTI.
Change-Id: Idd120c50f3205be116a22af83029b1560876fa36