[baremetal] Add unhold provision state verb support

Adds support for passing the "unhold" provision state verb
to Ironic. The underlying feature added allows step executions
for cleaning/provisioning (and later service), to pause operations
pending external intervention. This "unhold" provision state verb
is that intervention which unpauses the underlying operation
allowing it to complete normally.

Change-Id: Ic833b1e2f50e3540c2455c161eed08931f023d59

openstack/baremetal/v1/_common.py

@@ -31,6 +31,7 @@ PROVISIONING_VERSIONS = {
     'provide': 4,
     'rescue': 38,
     'unrescue': 38,
+    'unhold': 85,
 }
 """API microversions introducing provisioning verbs."""
 

openstack/baremetal/v1/node.py

@@ -100,7 +100,7 @@ class Node(_common.ListMixin, resource.Resource):
     )
 
     # Ability to query for parent_node, and view the field.
-    _max_microversion = '1.83'
+    _max_microversion = '1.85'
 
     # Properties
     #: The UUID of the allocation associated with this node. Added in API

openstack/tests/unit/baremetal/v1/test_node.py

@@ -383,6 +383,18 @@ class TestNodeSetProvisionState(base.TestCase):
             retriable_status_codes=_common.RETRIABLE_STATUS_CODES,
         )
 
+    def test_set_provision_state_unhold(self):
+        result = self.node.set_provision_state(self.session, 'unhold')
+
+        self.assertIs(result, self.node)
+        self.session.put.assert_called_once_with(
+            'nodes/%s/states/provision' % self.node.id,
+            json={'target': 'unhold'},
+            headers=mock.ANY,
+            microversion='1.85',
+            retriable_status_codes=_common.RETRIABLE_STATUS_CODES,
+        )
+
 
 @mock.patch.object(node.Node, '_translate_response', mock.Mock())
 @mock.patch.object(node.Node, '_get_session', lambda self, x: x)