Add unit test

[scottnuma]

• Sort into a couple folders: mentor_matching, data, docs
• Add unit testing structure

[j-m-h]

So it looks like right now assign.py is pointing to the wrong location for the mentor and team data--it assumes that assign.py is in the root directory, but it's actually one level down. (This is a fairly easy fix)

A bigger potential problem is that if (more like when) the input format changes from year to year, we're also going to have to change the unit test to fit that format. idk if that's that big a problem, but my goal here was kinda to make changes as easy as possible so that this can be used from year to year even if the people who originally worked on it are no longer around.

Perhaps as an alternative to unit tests (although I'm sure this isn't as good coding practice), we could just put something in the readme saying to make sure to run the code locally and ensure that it works before pushing (that's honestly how I found the issues with the enums and the file location).

[scottnuma]

Hmm - you make a good point on the need to change around in response to the form. I think rather than per function unit, integration tests would be better:

• test to run the entire program on sample data
• test to parse mentor data
• test to parse uhh school data

Keeping these should ensure stuff stays in a non-broken state, while leaving all the internal workings to be abstracted away.

[scottnuma]

Moved assign.py --> top level main.py
Applied a linter