Set min version to test node retirement

Splitting functional tests for node retirement to a different
class to set minimum supported version.

Change-Id: Ib9b6dba8f5fbb870faecf03ae0e49cfe814d31e0

openstack/tests/functional/baremetal/test_baremetal_node.py

@@ -269,6 +269,11 @@ class TestBareMetalNode(base.BaseBaremetalTest):
         self.assertTrue(node.is_maintenance)
         self.assertEqual(reason, node.maintenance_reason)
 
+
+class TestNodeRetired(base.BaseBaremetalTest):
+
+    min_microversion = '1.61'
+
     def test_retired(self):
         reason = "I'm too old for this s...tuff!"