old_contents: from setuptools import setup, Extension
  
  setup(name='_pynet',
        version='0.0.1',
        ext_modules=[Extension(name='_pynet',
                               sources=['src/_pynetmodule.c'],
                               )],
        )
  
new_contents: from distutils.core import setup, Extension
  
  setup(name='_pynet',
        version='0.0.1',
        ext_modules=[Extension(name='_pynet',
                               sources=['src/_pynetmodule.c'],
                               )],
        )
  
subject: remove setuptools dependency