Uninstallable using Python 2 (due to cmd2 dropping Py2 support)

[Dan Watkins]

cmd2 0.9.0 dropped support for Python 2[0], and therefore cliff can't install when using Python 2. For example[1]:

2018-05-30 06:13:12.357886 | ubuntu-xenial | Collecting cmd2>=0.6.7 (from cliff>=2.8.0->stestr>=2.0.0->-r /home/zuul/src/git.openstack.org/openstack-infra/jenkins-job-builder/test-requirements.txt (line 12))
2018-05-30 06:13:12.358209 | ubuntu-xenial | Downloading http://mirror.mtl01.inap.openstack.org/pypi/packages/98/b9/d0f52184579ab8cdff09bd7e786f24de14b3c8a6120ecf94f2dd33143cf4/cmd2-0.9.1.tar.gz (135kB)
2018-05-30 06:13:12.358353 | ubuntu-xenial | cmd2 requires Python '>=3.4' but the running Python is 2.7.12
2018-05-30 06:13:12.358383 | ubuntu-xenial |
2018-05-30 06:13:12.359220 | ubuntu-xenial | ERROR: could not install deps [-r/home/zuul/src/git.openstack.org/openstack-infra/jenkins-job-builder/test-requirements.txt]; v = InvocationError('/home/zuul/src/git.openstack.org/openstack-infra/jenkins-job-builder/.tox/py27/bin/pip install -r/home/zuul/src/git.openstack.org/openstack-infra/jenkins-job-builder/test-requirements.txt (see /home/zuul/src/git.openstack.org/openstack-infra/jenkins-job-builder/.tox/py27/log/py27-1.log)', 1)

[0] https://github.com/python-cmd2/cmd2/releases/tag/0.9.0
[1] From http://logs.openstack.org/96/571096/1/check/tox-py27/dec961e/job-output.txt.gz

[Doug Hellmann (doug-hellmann)]

This should be fixed with cliff 2.12.0.

[Sorin Sbarnea (ssbarnea)]

I cannot believe how many projects were broken because of this recent change in cmd2, still adding workarounds to requirements:

cmd2!=0.8.3,<0.9.0;python_version<'3.0' # MIT
cmd2!=0.8.3;python_version>='3.0' # MIT