run_test.sh uses pep8 not flake8

[Adam Young]

pep8 has been replaced with flake8 for the gate. If we run pep8, we miss some of the checks that happen upstream, and patches won't merge

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/31678

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/31678
Committed: http://github.com/openstack/keystone/commit/766da68c4df200f3656cbdae47b32c3822ba8c77
Submitter: Jenkins
Branch: master

commit 766da68c4df200f3656cbdae47b32c3822ba8c77
Author: Dolph Mathews <email address hidden>
Date: Tue Jun 4 12:27:11 2013 -0500

    run_tests.sh should use flake8 (bug 1180609)

    Existing flags (e.g. --pep8) are intentionally left alone.

    Change-Id: I300aaee17294b88c7d1ba4daad462af407c67d4f

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/39912

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/39912
Committed: http://github.com/openstack/python-keystoneclient/commit/63c755e1ae0be13d7ee233ffae5508f1cca97a51
Submitter: Jenkins
Branch: master

commit 63c755e1ae0be13d7ee233ffae5508f1cca97a51
Author: Jaime Gil de Sagredo Luna <email address hidden>
Date: Fri Aug 2 14:21:07 2013 +0200

    Use flake8 in run_tests.sh and updated ignore flake8 rules with tox.ini

    Change-Id: I9ec82e4ddbaa8c9f256ff962c48dfb556948b32d
    Fixes: bug #1180609