Add job builds discarder

Change-Id: I7a4a46826b547731b91f2ed1f58927ba4ddd4455
diff --git a/jenkins/client/job/deploy/update/virt_snapshot.yml b/jenkins/client/job/deploy/update/virt_snapshot.yml
index 0388ed1..be92c8d 100644
--- a/jenkins/client/job/deploy/update/virt_snapshot.yml
+++ b/jenkins/client/job/deploy/update/virt_snapshot.yml
@@ -10,6 +10,11 @@
         manage-virt-snapshot:
           type: workflow-scm
           concurrent: true
+          discard:
+            build:
+              keep_num: 10
+            artifact:
+              keep_num: 10
           display_name: "Deploy - virt snapshot VM"
           scm:
             type: git