It is installed everywhere now, there is no practical way to use python without it.
Simplify setup.py by always relying on setuptools
Coverage decreased (-0.01%) to 72.568% when pulling 3bd1e6a on alex:patch-4 into a14d266 on paramiko:master.
+1, this is recommended practice now adays.
God bless code more than a decade old!
Changelog closes #729
Backported to 1.15.x