st2client could not be installed when setuptools>=50.0.0

SUMMARY

Provide a quick summary of your bug report.

STACKSTORM VERSION

not relevant

OS, environment, install method

not relevant

Steps to reproduce the problem

1. run python image -> docker run --rm -it --entrypoint=sh python:3.7
2. install setuptools>=50.0.0 pip install setuptools>=50.0.0
3. try to install st2client in the container pip install st2client==3.2.0

however, when setuptools<50.0.0 was installed, st2client can be installed.

Expected Results

exceted st2client can be installed.

Actual Results

error occurs when installing

# pip install st2client==3.2.0
Collecting st2client==3.2.0
  Downloading st2client-3.2.0.tar.gz (104 kB)
     |████████████████████████████████| 104 kB 134 kB/s
    ERROR: Command errored out with exit status 1:
     command: /usr/local/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-f4z91qt3/st2client/setup.py'"'"'; __file__='"'"'/tmp/pip-install-f4z91qt3/st2client/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-o1xxfeb4
         cwd: /tmp/pip-install-f4z91qt3/st2client/
    Complete output (17 lines):
    /usr/local/lib/python3.7/site-packages/_distutils_hack/__init__.py:30: UserWarning: Setuptools is replacing distutils.
      warnings.warn("Setuptools is replacing distutils.")
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-f4z91qt3/st2client/setup.py", line 63, in <module>
        'st2 = st2client.shell:main'
      File "/usr/local/lib/python3.7/site-packages/setuptools/__init__.py", line 152, in setup
        _install_setup_requires(attrs)
      File "/usr/local/lib/python3.7/site-packages/setuptools/__init__.py", line 145, in _install_setup_requires
        dist.parse_config_files(ignore_option_errors=True)
      File "/usr/local/lib/python3.7/site-packages/setuptools/dist.py", line 665, in parse_config_files
        self._parse_config_files(filenames=filenames)
      File "/usr/local/lib/python3.7/site-packages/setuptools/dist.py", line 572, in _parse_config_files
        filenames = self.find_config_files()
      File "/usr/local/lib/python3.7/site-packages/setuptools/_distutils/dist.py", line 353, in find_config_files
        sys_dir = os.path.dirname(sys.modules['distutils'].__file__)
    KeyError: 'distutils'
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

Reproduce the failure in the Python 3.7 container using the listed setuptools and st2client versions. Start with st2client/setup.py around line 63 and the setuptools traceback, then verify that st2client installs successfully with setuptools>=50.0.0 and that the st2 command remains available.