Add human readable logging callback plugin for func testing

This should make it easier to understand check and gate
failures by analyzing the logs.

Change-Id: If2d73ae6cfcb0234be7d121965f7472b367181e7

tox.ini

@@ -15,6 +15,7 @@ whitelist_externals =
     bash
     git
     rm
+    wget
 setenv =
     VIRTUAL_ENV={envdir}
     ANSIBLE_HOST_KEY_CHECKING = False
@@ -104,6 +105,9 @@ commands =
     rm -rf {homedir}/.ansible
     git clone https://git.openstack.org/openstack/openstack-ansible-plugins \
               {homedir}/.ansible/plugins
+    # This plugin makes the ansible-playbook output easier to read
+    wget -O {homedir}/.ansible/plugins/callback/human_log.py \
+      https://gist.githubusercontent.com/cliffano/9868180/raw/f360f306b3c6d689734a6aa8773a00edf16a0054/human_log.py
     ansible-playbook -i {toxinidir}/tests/inventory \
                      -e "rolename={toxinidir}" \
                      {toxinidir}/tests/test.yml