Add simple verification that orderflow is configured correctly

tests/test_configuration.py

@@ -992,6 +992,20 @@ def test__validate_consumers(default_conf, caplog) -> None:
     assert log_has_re("To receive best performance with external data.*", caplog)
 
 
+def test__validate_orderflow(default_conf) -> None:
+    conf = deepcopy(default_conf)
+    conf['exchange']['use_public_trades'] = True
+    with pytest.raises(OperationalException,
+                       match="Orderflow is a required configuration key when using public trades."):
+        validate_config_consistency(conf)
+
+    conf.update({'orderflow': {
+        "scale": 0.5,
+    }})
+    # Should pass.
+    validate_config_consistency(conf)
+
+
 def test_load_config_test_comments() -> None:
     """
     Load config with comments