Set setup.cfg encoding

[stanislavlevin]

Fixes: #1211

[gaborbernat]

Can you detail what and where broke without this? Thanks!

[stanislavlevin]

Sure,

(Pdb) bt
  /usr/src/RPM/BUILD/python-module-tox-3.8.0/setup.py(18)<module>()
-> package_dir={"": "src"},
  /usr/lib/python2.7/site-packages/setuptools/__init__.py(145)setup()
-> _install_setup_requires(attrs)
  /usr/lib/python2.7/site-packages/setuptools/__init__.py(138)_install_setup_requires()
-> dist.parse_config_files(ignore_option_errors=True)
  /usr/lib/python2.7/site-packages/setuptools/dist.py(703)parse_config_files()
-> self._parse_config_files(filenames=filenames)
  /usr/lib/python2.7/site-packages/setuptools/dist.py(600)_parse_config_files()
-> (parser.read_file if six.PY3 else parser.readfp)(reader)
  /usr/lib64/python2.7/ConfigParser.py(324)readfp()
-> self._read(fp, filename)
> /usr/lib64/python2.7/ConfigParser.py(479)_read()
-> line = fp.readline()
(Pdb) fp
<_io.TextIOWrapper name='setup.cfg' encoding='ANSI_X3.4-1968'>
(Pdb) fp.readline()
*** UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 345: ordinal not in range(128)
(Pdb) 

[stanislavlevin]

setup.cfg contains Unicode symbols like:

author = Holger Krekel, Oliver Bestwalter, Bernát Gábor and others