remove vestigial python2 references

docs/contributing.rst

@@ -165,7 +165,7 @@ to stick to PEP8_ when writing new code. If you're refactoring old code, it
 would be great if you were to fix it to make it PEP8 compliant as well.
 
 To check whether the code is PEP8 compliant, you can use pycodestyle_. You can
-easily install it with pip by using ``pip2 install pycodestyle``.
+easily install it with pip by using ``pip3 install pycodestyle``.
 
 .. _PEP8: https://www.python.org/dev/peps/pep-0008/
 .. _pycodestyle: https://pypi.python.org/pypi/pycodestyle

overviewer_core/progressbar.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python2
+#!/usr/bin/env python3
 # -*- coding: iso-8859-1 -*-
 #
 # progressbar  - Text progressbar library for python.