test: install update mock (#349)

* install update test

* lint fix

* fix

* fix

---------

Co-authored-by: Anna Lushnikova <loosla@users.noreply.github.com>

tests/mocked/test_databases.py

@@ -1000,6 +1000,23 @@ def test_databases_update_online_migration(mock_client: Client, mock_client_url)
     assert expected == resp
 
 
+@responses.activate
+def test_databases_install_update(mock_client: Client, mock_client_url):
+    """Mocks the databases install update."""
+
+    cluster_uuid = "9cc10173-e9ea-4176-9dbc-a4cee4c4ff30"
+
+    responses.add(
+        responses.PUT,
+        f"{mock_client_url}/v2/databases/{cluster_uuid}/install_update",
+        status=204,
+    )
+
+    resp = mock_client.databases.install_update(cluster_uuid)
+
+    assert resp is None
+
+
 @responses.activate
 def test_databases_update_region(mock_client: Client, mock_client_url):
     """Mocks the databases update firewall rules operation."""