Add ability to set event_time_to_live

In order to have ability to clean events after certain time
event_time_to_live should be set.

Change-Id: Iaa40796108cacd4b3bcbd581b956c30e2e304fc2
Related-Prod: https://mirantis.jira.com/browse/PROD-20388
diff --git a/tests/pillar/server_single.sls b/tests/pillar/server_single.sls
index 44fe17c..3ea39db 100644
--- a/tests/pillar/server_single.sls
+++ b/tests/pillar/server_single.sls
@@ -2,6 +2,7 @@
   server:
     enabled: true
     version: pike
+    event_time_to_live: 10
     bind:
       host: 127.0.0.1
       port: 8977