Ensure that role tests pin pip/setuptools/wheel

Currently the role tests use whatever versions of pip,
setuptools and wheel are already installed on the host.

When a version of these tools changes it often causes
problems for our testing.

This will ensure that we use a known good set of pins
which is maintained in the general SHA bumping process.

Change-Id: Ibdbe49fe6d408627762185aaa20a609f6b5e2343

defaults/main.yml

@@ -86,6 +86,8 @@ pip_install_build_packages: yes
 # wheel and any other packages which must be installed when pip installs.
 pip_packages:
   - pip
+  - setuptools
+  - wheel
 
 pip_required_pip_packages: []
 

tox.ini

@@ -75,6 +75,7 @@ commands =
 [testenv:ansible]
 deps =
     {[testenv]deps}
+    -rhttps://git.openstack.org/cgit/openstack/openstack-ansible/plain/global-requirement-pins.txt
     -rhttps://git.openstack.org/cgit/openstack/openstack-ansible-tests/plain/test-ansible-deps.txt