Use 0.6.1, 0.6.2 Cirros images instead of 0.5.x

Related-PROD: PROD-37187
Change-Id: Ia3acdbb546e0f2a473fabbe21104a0e47821f101
diff --git a/tempest/tempest_ext.conf b/tempest/tempest_ext.conf
index 6a18040..e095319 100644
--- a/tempest/tempest_ext.conf
+++ b/tempest/tempest_ext.conf
@@ -35,7 +35,7 @@
 fixed_subnet_name = cvp.subnet.1
 disable_ssl_certificate_validation = True
 image_ref = cvp.tiny
-minimal_image_ref = cvp.cirros.35
+minimal_image_ref = cvp.cirros.61
 fixed_network_name = cvp.net.1
 build_timeout = 180
 ssh_timeout = 30