Test are unable to run because of old tox version

[Maciej Jozefczyk]

After latest changes on tox.ini:
http://git.openstack.org/cgit/openstack/neutron/commit/?id=0479f0f9d2bf8fb857b2c683b5d7310e6dd9bf15

configuration file is unable to be parsed, because of error:

# tox -e py27
Traceback (most recent call last):
  File "/usr/local/bin/tox", line 11, in <module>
    sys.exit(cmdline())
  File "/usr/local/lib/python2.7/dist-packages/tox/session.py", line 38, in main
    config = prepare(args)
  File "/usr/local/lib/python2.7/dist-packages/tox/session.py", line 26, in prepare
    config = parseconfig(args)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 229, in parseconfig
    parseini(config, inipath)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 729, in __init__
    self.make_envconfig(name, section, reader._subs, config)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 760, in make_envconfig
    res = meth(env_attr.name, env_attr.default)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 929, in getargvlist
    return _ArgvlistReader.getargvlist(self, s)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1097, in getargvlist
    replaced = reader._replace(current_command)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 973, in _replace
    return Replacer(self, crossonly=crossonly).do_replace(value)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 992, in do_replace
    return self.RE_ITEM_REF.sub(self._replace_match, x)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1021, in _replace_match
    return self._replace_substitution(match)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1067, in _replace_substitution
    val = self._substitute_from_other_section(sub_key)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1058, in _substitute_from_other_section
    crossonly=self.crossonly)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 973, in _replace
    return Replacer(self, crossonly=crossonly).do_replace(value)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 992, in do_replace
    return self.RE_ITEM_REF.sub(self._replace_match, x)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1021, in _replace_match
    return self._replace_substitution(match)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1067, in _replace_substitution
    val = self._substitute_from_other_section(sub_key)
  File "/usr/local/lib/python2.7/dist-packages/tox/config.py", line 1061, in _substitute_from_other_section
    "substitution key %r not found" % key)
tox.ConfigError: ConfigError: substitution key 'posargs' not found

It is directly connected to solved #issue279 described here:
https://tox.readthedocs.io/en/latest/changelog.html

We need to change minimum version of tox from 2.3.1 to 2.3.2.
Gates are passing, because they use tox from pip (tox-2.7.0 ) instead from Ubuntu system.

*Reproduce Steps
** git clone https://github.com/openstack/neutron.git
** pip install tox==2.3.1
** tox -e py27

* Versions
** Version: master upstream neutron
** Tox version: 2.3.1

[OpenStack Infra (hudson-openstack)]

Related fix proposed to branch: master
Review: https://review.openstack.org/470943

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/470943
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=db9ac80072ee78673f9846f8217b45dee23cf3a4
Submitter: Jenkins
Branch: master

commit db9ac80072ee78673f9846f8217b45dee23cf3a4
Author: Maciej Józefczyk <email address hidden>
Date: Mon Jun 5 14:08:14 2017 +0200

    Update minimum tox version to 2.3.2

    After latest changes on tox.ini we need to change minimum
    version of tox to 2.3.2. Problem is described in tox changelog
    as #issue279. Without this change tests are unable to run.

    Change-Id: I458cf0d5e8927cf11a44b49ecfb5178a228aafaf
    Closes-Bug: #1695888

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 11.0.0.0b2 development milestone.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ocata
Review: https://review.openstack.org/474272

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/474273

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/474272
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=243108232f4f8a4eb578643bf9aa38e918100311
Submitter: Jenkins
Branch: stable/ocata

commit 243108232f4f8a4eb578643bf9aa38e918100311
Author: Maciej Józefczyk <email address hidden>
Date: Mon Jun 5 14:08:14 2017 +0200

    Update minimum tox version to 2.3.2

    After latest changes on tox.ini we need to change minimum
    version of tox to 2.3.2. Problem is described in tox changelog
    as #issue279. Without this change tests are unable to run.

    Conflicts:
     tox.ini

    Change-Id: I458cf0d5e8927cf11a44b49ecfb5178a228aafaf
    Closes-Bug: #1695888
    (cherry picked from commit db9ac80072ee78673f9846f8217b45dee23cf3a4)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/474273
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=1766a8ee18bf1e0351d965571c8e3434b87a74ee
Submitter: Jenkins
Branch: stable/newton

commit 1766a8ee18bf1e0351d965571c8e3434b87a74ee
Author: Maciej Józefczyk <email address hidden>
Date: Mon Jun 5 14:08:14 2017 +0200

    Update minimum tox version to 2.3.2

    After latest changes on tox.ini we need to change minimum
    version of tox to 2.3.2. Problem is described in tox changelog
    as #issue279. Without this change tests are unable to run.

    Conflicts:
     tox.ini

    Change-Id: I458cf0d5e8927cf11a44b49ecfb5178a228aafaf
    Closes-Bug: #1695888
    (cherry picked from commit db9ac80072ee78673f9846f8217b45dee23cf3a4)

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 9.4.1 release.

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron 10.0.3 release.