change test group 3 expected output to be clearer

[fleather2]

For test group 3, the expected output for the first command is "uploaded at Python.txt." Could just be my interpretation, but to me this doesn't make sense.

My suggestion is to change it to "uploaded Python.txt at 2021-07-01T12:00:00", so that the programmer is forced to include the newly-given time. Also, I think the output should be ordered by time, instead of by input order. This would create an additional challenge for the programmer to show that the storage system is actually capable of executing future events. (If this route is taken, then datetime should be imported, too)

Maybe I'm misinterpreting the purpose of the tests, though. Thoughts on this?