ImportError: cannot import name 'python_2_unicode_compatible' from 'django.utils.encoding'

[sweta-creoit]

Checklist

• [x] I have verified that I am using a GIS-enabled database, such as PostGIS or Spatialite.
• [x] I have verified that that issue exists against the master branch of django-cities.
• [x] I have searched for similar issues in both open and closed tickets and cannot find a duplicate.
• [x] I have reduced the issue to the simplest possible case.
• [ ] I have included a failing test as a pull request. (If you are unable to do so we can still accept the issue.)

Steps to reproduce

ERROR:(/cities/models.py) from django.utils.encoding import python_2_unicode_compatible ImportError: cannot import name 'python_2_unicode_compatible' from 'django.utils.encoding'

As per latest version of Django==Django==3.0.2, the python_2_unicode_compatible has been moved to six.py , need to get updated So that django-cities/models.py can pick from six.py package.

Expected behavior

In /cities/models.py , the import should be: from six import python_2_unicode_compatible

Actual behavior

In /cities/models.py , the import is: from django.utils.encoding import python_2_unicode_compatible

[blag]

Fixed by #214. I'll try to get around to updating the tests and merging that PR soon.