conditionally registrar inspector

Author: fgregg

pytest_flask_sqlalchemy/fixtures.py

@@ -110,7 +110,9 @@ class EngineMock(mocker.MagicMock):
 
     # Calls to execution_options should return this mocked engine
     engine.execution_options.return_value = engine
-    sa.inspection._registrars[EngineMock] = sa.engine.Inspector._engine_insp
+
+    if version.parse(sa.__version__) >= version.parse('1.4'):
+        sa.inspection._registrars[EngineMock] = sa.engine.Inspector._engine_insp
 
     # References to `Engine.dialect` should redirect to the Connection (this
     # is primarily useful for the `autoload` flag in SQLAlchemy, which references