Merge pull request #4367 from edx/nadeem/upgrade-mms-agent

Upgrade mongo agent (OPS-2290)

playbooks/roles/mongo_mms/defaults/main.yml

@@ -6,10 +6,10 @@ os_version: "ubuntu1604"
 
 agents:
   - agent: mongodb-mms-monitoring-agent
-    version:  "6.0.0.381-1"
+    version:  "6.3.0.401-1"
     config: "/etc/mongodb-mms/monitoring-agent.config"
     dir: "monitoring"
   - agent: mongodb-mms-backup-agent
-    version: "5.8.0.655-1"
+    version: "6.4.0.734-1"
     config: "/etc/mongodb-mms/backup-agent.config"
     dir: "backup"