Define basestring, unicode using feature detection
Define basestring, unicode using feature detection

Use the Python porting best practice [use feature detection instead of version detection](https://docs.python.org/3/howto/pyporting.html#use-feature-detection-instead-of-version-detection) to define basestring() and unicode() in order to placate flake8.
oaubert/python-vlc,oaubert/python-vlc