Python 3 support

[blinklet]

Since Python 2 will not be maintained after January 1, 2020, the Wistar code base should be tested in Python 3 and incompatibilities resolved. This will allow users to run Wistar on newer Linux distributions in the future.

[Mikiwis]

"libvirt-python" can not be built as it requires Python 3

This means I can not use it at all. #BlinkingRed

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root@wistar:/opt/wistar# source /opt/wistar/bin/activate
(wistar) root@wistar:/opt/wistar# pip install libvirt-python
DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 is no longer maintained. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support
Collecting libvirt-python
Using cached libvirt-python-6.1.0.tar.gz (196 kB)
ERROR: Command errored out with exit status 1:
command: /opt/wistar/bin/python -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-tvuTC4/libvirt-python/setup.py'"'"'; file='"'"'/tmp/pip-install-tvuTC4/libvirt-python/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-install-tvuTC4/libvirt-python/pip-egg-info
cwd: /tmp/pip-install-tvuTC4/libvirt-python/
Complete output (1 lines):
libvirt-python requires Python 3.x to build
----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.