YAPF bails on utf-8 encoded files.

e.g. https://github.com/Ezhil-Language-Foundation/open-tamil/blob/master/solthiruthi/peyarchorkal.py file will not be reformatted correctly.

    sys.exit(main(sys.argv))

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/__init__.py", line 135, in main

    verbose=args.verbose)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/__init__.py", line 204, in FormatFiles

    in_place, print_diff, verify, quiet, verbose)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/__init__.py", line 233, in _FormatFile

    logger=logging.warning)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/yapflib/yapf_api.py", line 100, in FormatFile

    verify=verify)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/yapflib/yapf_api.py", line 147, in FormatCode

    tree = pytree_utils.ParseCodeToTree(unformatted_source)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/site-packages/yapf/yapflib/pytree_utils.py", line 121, in ParseCodeToTree

    tree = parser_driver.parse_string(code, debug=False)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib2to3/pgen2/driver.py", line 106, in parse_string

    return self.parse_tokens(tokens, debug)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib2to3/pgen2/driver.py", line 71, in parse_tokens

    if p.addtoken(type, value, (prefix, start)):

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib2to3/pgen2/parse.py", line 116, in addtoken

    ilabel = self.classify(type, value, context)

  File "/Library/Frameworks/Python.framework/Versions/3.6/lib/python3.6/lib2to3/pgen2/parse.py", line 172, in classify

    raise ParseError("bad token", type, value, context)

lib2to3.pgen2.parse.ParseError: bad token: type=58, value='ப', context=('', (23, 22))