Nuanced unit testing for the rest of the endpoints

[Ericy1]

Currently, there are unit tests for listFiles, putFile, and generateKey.

We need a unit test for:

1. getFile

We also need more detailed testing for the current endpoints. For example, putFile only checks that the response code is 201, but we can check the response body for validity, too. things like response body size > 0, regex to match case, etc.

[gavin2059]

Remaining TODOs:

1. find a way to compare two files to each other and see that they're the same in Python. we can use this to test putfile, getfile, etc.
2. write tests for putObject and getObject using (1).
3. write tests for listObject