Add automatic release job triggered by tag

Currently put it in pre-release pipeline to test that it's ok.

Change-Id: I791478464ed59933273bb0e5f88f3636074c6729

tox.ini

@@ -111,3 +111,13 @@ deps =
     -r{toxinidir}/test-requirements-2.11.txt
 passenv = {[testenv:ansible]passenv}
 commands = {[testenv:ansible]commands}
+
+[testenv:galaxy-release]
+deps =
+    ansible-core
+commands =
+    /usr/bin/mkdir -p /tmp/collection_built
+    /usr/bin/bash -ec 'rm -rf /tmp/collection_built/*'
+    /usr/bin/sed -i "s/version:.*/version: {env:VERSION_TAG}/" {toxinidir}/galaxy.yml
+    ansible-galaxy collection build {toxinidir} --output-path /tmp/collection_built/ --force
+    ansible-galaxy collection publish /tmp/collection_built/openstack-cloud-{env:VERSION_TAG}.tar.gz --token {env:API_GALAXY_TOKEN}