Add way to run Python tests

[OpenStack Infra]

https://review.openstack.org/157319
commit 4f12918d5b9a2a866ce095f8f5bdc74b467bc8ef
Author: Sebastian Kalinowski <email address hidden>
Date: Thu Feb 19 11:34:10 2015 +0100

    Add way to run Python tests

    Added script to easily run Python tests in fuel-library.
    Script is located in ./utils/jenkins/python_run_tests.sh and
    uses tox to create environments and py.test as a test runner.

    Usage of the script can be learn from running it with '-h' arg:
     ./python_run_tests.sh -h

    Tests include running all found Python tests as well
    'flake8' with 'hacking' checks in newest version.

    Requirements for tests could be found in
    ./utils/jenkins/python-test-requirements.txt

    tox.ini. is located in
    ./utils/jenkins/tox.ini

    Disabled all flake8 checks in all currently failing files.

    DocImpact
    Change-Id: I283333c48ac53d7baa0a9bb04558d7317bdcec11