ansible-lint: install zuul

Install zuul so that ansible-lint has zuul integration and will not fail
some tests.

for this, move all requirements directly into tox.ini so that not every
job needs to install them.

Change-Id: I2b16600fad4c18f790e842b200ae21fd90051077

test-requirements.txt

@@ -1,6 +1,3 @@
 hacking>=0.10,<0.11
 bashate>=0.2
 -e git://git.openstack.org/openstack-infra/nodepool#egg=nodepool
-
-ansible<2.4.0
-ansible-lint

tox.ini

@@ -16,7 +16,16 @@ commands =
 
 [testenv:ansible-linters]
 # TODO(jaegerandi): merge this in linters job once it works fine
+# zuul needs python3
+basepython = python3
+deps = 
+     # Zuul is required to supply the zuul ansible modules for ansible-lint
+     -egit+https://git.openstack.org/openstack-infra/zuul@feature/zuulv3#egg=zuul
+     ansible<2.4.0
+     ansible-lint
 whitelist_externals = bash
+setenv =
+  ANSIBLE_LIBRARY= {envdir}/src/zuul/zuul/ansible/library
 passenv =
   # NOTE(pabelanger): if you'd like to run tox -elinters locally, you'll need
   # to export ANSIBLE_ROLES_PATH pointing to the currect repos.