Installation of ssh-import-id==5.6 fails if requests package is not already installed

Our docker container installs packages via requirements.txt. This means that initially none of the packages are installed. During installation, ssh-import-id==5.6 (the latest on PyPi) fails when setup.py attempts to import the requests package as the result of setup.py importing `from ssh_import_id import __version__`.

I took a look at the latest setup.py in master and it appears to have a fix for this, but no new version has been released to PyPi since 5.6, so the install fails.

Could you please kindly push a new version of this package to PyPi?

Here is the error message:

```
    ERROR: Command errored out with exit status 1:
     command: /Users/vkruglik/git/cdho-backend/venv/bin/python3 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/setup.py'"'"'; __file__='"'"'/private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/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 /private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/pip-egg-info
         cwd: /private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/
    Complete output (7 lines):
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/setup.py", line 20, in <module>
        from ssh_import_id import __version__
      File "/private/var/folders/tg/vy8v5jyd0rgc643cfnc_yqjh0000gy/T/pip-install-nu3gicid/ssh-import-id/ssh_import_id/__init__.py", line 25, in <module>
        import requests
    ModuleNotFoundError: No module named 'requests'
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.
```