Remove meaningless commits

Author: Zhen

test/session_test.py

@@ -208,8 +208,6 @@ def test_can_rollback_transaction(self):
 
             tx.rollback()
 
-            # I do not know how this framework works to close the tx after each method call
-            # But it should be closed due to the rollback
             # Check the property value
             result = session.run("MATCH (a) WHERE id(a) = {n} "
                                   "RETURN a.foo", {"n": node_id})