auth_file: add tag to File resource

Add a Puppet tag to the File resource that manages '/root/openrc'.
It will allow in puppet-keystone to set some orchestration to make sure
/root/openrc is created *after* managing admin resources.

Change-Id: I203728a25ef8a33787760672b17e61539ad820c3

manifests/auth_file.pp

@@ -114,6 +114,7 @@ class openstack_extras::auth_file(
     owner   => 'root',
     group   => 'root',
     mode    => '0700',
+    tag     => ['openrc'],
     content => template('openstack_extras/openrc.erb')
   }
 }