Install zuul to access zuul_console

When we lint our playbooks, we need to also have zuul install our
custom action plugins.

Also default to python3 so we can properly install zuul into tox.

Change-Id: Ib7e39e43005aa73c9d482af6becef3408d097e15
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

test-requirements.txt

@@ -8,3 +8,4 @@ ansible-lint
 bashate>=0.2
 sphinx>=1.5.1,<1.6.0 # BSD
 oslosphinx>=4.7.0 # Apache-2.0
+-e git://git.openstack.org/openstack-infra/zuul@feature/zuulv3#egg=zuul

tox.ini

@@ -4,6 +4,7 @@ skipsdist = True
 envlist = linters
 
 [testenv]
+basepython = python3
 install_command = pip install {opts} {packages}
 deps = -r{toxinidir}/test-requirements.txt
 commands =
@@ -23,6 +24,7 @@ commands = python setup.py build_sphinx
 [testenv:linters]
 setenv =
   ANSIBLE_CONFIG = {toxinidir}/tests/ansible.cfg
+  ANSIBLE_LIBRARY= {envdir}/src/zuul/zuul/ansible/library
 whitelist_externals = bash
 commands =
   flake8 {posargs}