Error to install greenswitch

[evangilo]

root@23e644173fda:/code# pip install greenswitch==0.0.11
Collecting greenswitch==0.0.11
  Using cached greenswitch-0.0.11.tar.gz (11 kB)
    ERROR: Command errored out with exit status 1:
     command: /usr/local/bin/python -c 'import io, os, sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-5zt_no30/greenswitch_1f6b24059d874ef88a8155b81b0dc22b/setup.py'"'"'; __file__='"'"'/tmp/pip-install-5zt_no30/greenswitch_1f6b24059d874ef88a8155b81b0dc22b/setup.py'"'"';f = getattr(tokenize, '"'"'open'"'"', open)(__file__) if os.path.exists(__file__) else io.StringIO('"'"'from setuptools import setup; setup()'"'"');code = f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-j4fonfg5
         cwd: /tmp/pip-install-5zt_no30/greenswitch_1f6b24059d874ef88a8155b81b0dc22b/
    Complete output (7 lines):
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-5zt_no30/greenswitch_1f6b24059d874ef88a8155b81b0dc22b/setup.py", line 9, in <module>
        readme = f.read()
      File "/usr/local/lib/python3.6/encodings/ascii.py", line 26, in decode
        return codecs.ascii_decode(input, self.errors)[0]
    UnicodeDecodeError: 'ascii' codec can't decode byte 0xc2 in position 2193: ordinal not in range(128)