tox -e pep8 reports an error on ubuntu 16.04

[Dmitry Guryanov]

tox -e pep8 reports an error on ubuntu 16.04 because it uses python 3 and raw_input() renamed to input() there:

:) dguryanov@dguryanov ~/dev/fuel-web $ tox -e pep8
pep8 installed: flake8==2.2.4,hacking==0.10.0,mccabe==0.2.1,pbr==0.11.1,pep8==1.5.7,pkg-resources==0.0.0,pyflakes==0.8.1,six==1.10.0
pep8 runtests: PYTHONHASHSEED='1982625001'
pep8 runtests: commands[0] | flake8 nailgun
nailgun/fuyaql/fuyaql.py:316:27: F821 undefined name 'raw_input'
                command = raw_input('fuel-yaql> ').strip()
                          ^
1
ERROR: InvocationError: '/home/dguryanov/dev/fuel-web/.tox/pep8/bin/flake8 nailgun'

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/336085

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/336085
Committed: https://git.openstack.org/cgit/openstack/fuel-web/commit/?id=80202eb7a8951d5dddae9ba3cf3d648d30abf7b8
Submitter: Jenkins
Branch: master

commit 80202eb7a8951d5dddae9ba3cf3d648d30abf7b8
Author: Dmitry Guryanov <email address hidden>
Date: Thu Jun 30 18:24:02 2016 +0300

    use input() instead of raw_input()

    raw_input() renamed to input() in python 3
    so let's import it from six module.

    Change-Id: Ic5dc5bc482ab61db61588c878e8c0d2dd6bb8752
    Closes-Bug: #1597810

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/mitaka
Review: https://review.openstack.org/378851

[OpenStack Infra (hudson-openstack)]

Change abandoned by Andreas Jaeger (<email address hidden>) on branch: stable/mitaka
Review: https://review.opendev.org/378851
Reason: This repo is retired now, no further work will get merged.