Keep more builds for tests

Change-Id: Idef9d235837c6b926ccbbe6f54bd4ebb50f2f447
diff --git a/jenkins/client/job/salt-models/tests.yml b/jenkins/client/job/salt-models/tests.yml
index 711cdf7..3eec219 100644
--- a/jenkins/client/job/salt-models/tests.yml
+++ b/jenkins/client/job/salt-models/tests.yml
@@ -140,7 +140,7 @@
           name: test-salt-model-node
           discard:
             build:
-              keep_num: 10
+              keep_num: 500
             artifact:
               keep_num: 10
           type: workflow-scm