Add a python script to test the simple corner cases of MVCC.
Add a python script to test the simple corner cases of MVCC.

eric-haibin-lin/peloton,eric-haibin-lin/peloton,eric-haibin-lin/peloton,eric-haibin-lin/peloton,eric-haibin-lin/peloton,eric-haibin-lin/peloton,eric-haibin-lin/peloton