Refactor packaging by introducing pbr.
    
    Since python-daemon distribution facing issues
    related to dependances management this commit
    try to avoid this kind of problem and try to
    simplify the project release management by using pbr.
    
    This commit introduce:
    - packaging metadata management by using configuration file;
    - introduce PEP 516;
    - introduce requirements file;
    - convert README to rst format for a better visualization on pagure and better compatibility with pbr.
    
    Using it:
    - install pbr (pip install pbr);
    - create a new tag (git tag 9.9.9)(by example);
    - build and dist (python setup.py build && python setup.py sdist);
    - publish your release on pypi by using twine or whatever you want.
    
    pbr[1] allow simplify python packaging by automatizing:
    - semver[2] management;
    - changelog generation;
    - authors file generation.
    
    [1] https://docs.openstack.org/pbr/latest/
    [2] https://semver.org/
    
    Co-authored-by: Hobbestigrou <hobbestigrou@erakis.eu>