Handle scheduler default filters as sequence

In order to add just additional filters on cluster level
instead of copy/paste all existing list plus additional ones.
Both string and sequence are supported since Queens version.

Change-Id: I55b5a045b4615e12788a358f25f47698d70653aa
diff --git a/tests/pillar/control_single.sls b/tests/pillar/control_single.sls
index 338d63b..f94743b 100644
--- a/tests/pillar/control_single.sls
+++ b/tests/pillar/control_single.sls
@@ -2,12 +2,23 @@
   controller:
     enabled: true
     networking: contrail
-    version: pike
+    version: queens
     security_group: false
     vncproxy_url: 127.0.0.1
     vnc_keymap: en-gb
     dhcp_domain: novalocal
-    scheduler_default_filters: "DifferentHostFilter,RetryFilter,AvailabilityZoneFilter,RamFilter,CoreFilter,DiskFilter,ComputeFilter,ComputeCapabilitiesFilter,ImagePropertiesFilter,ServerGroupAntiAffinityFilter,ServerGroupAffinityFilter"
+    scheduler_default_filters:
+      - DifferentHostFilter
+      - RetryFilter
+      - AvailabilityZoneFilter
+      - RamFilter
+      - CoreFilter
+      - DiskFilter
+      - ComputeFilter
+      - ComputeCapabilitiesFilter
+      - ImagePropertiesFilter
+      - ServerGroupAntiAffinityFilter
+      - ServerGroupAffinityFilter
     cpu_allocation_ratio: 16.0
     ram_allocation_ratio: 1.5
     disk_allocation_ratio: 1.0