Add playbook for cleaning workspaces

Sometimes we need to clean the workspaces. While we have a command
documented, go ahead and make a playbook for it.

Change-Id: I1887dec24563811a71157c000b2d8ae9b7850d6a

doc/source/gerrit.rst

@@ -474,7 +474,7 @@ To rename a project:
    changing, gate jobs may fail due to outdated remote URLs. Clear
    the workspaces on persistent Jenkins slaves to mitigate this::
 
-     sudo salt '*.slave.openstack.org' cmd.run 'rm -rf ~jenkins/workspace/*PROJECT*'
+     sudo ansible-playbook -f 10 /etc/ansible/clean_workspaces.yaml --extra-vars "project=PROJECTNAME"
 
 #. Again, if this is an org move rather than a rename and the GitHub
    project has been created but is empty, trigger replication to

modules/openstack_project/files/ansible/clean_workspaces.yaml

@@ -0,0 +1,4 @@
+---
+- hosts: *.slave.openstack.org
+  tasks:
+    - shell: 'rm -rf ~jenkins/workspace/*{{ project }}*'

modules/openstack_project/manifests/puppetmaster.pp

@@ -123,4 +123,9 @@ class openstack_project::puppetmaster (
     require => Class[ansible],
   }
 
+  file { '/etc/ansible/clean_workspaces.yaml':
+    ensure  => present,
+    source  => 'puppet:///modules/openstack_project/ansible/clean_workspaces.yaml',
+    require => Class[ansible],
+  }
 }