Complete Sprint 3 practice TDD coursework

### Link to the coursework

https://github.com/CodeYourFuture/Module-Structuring-and-Testing-Data/tree/main/Sprint-3/2-practice-tdd

### Why are we doing this?

These challenges are designed to develop your problem-solving skills.

### Maximum time in hours

2

### How to get help

Share your blockers in your class channel
https://curriculum.codeyourfuture.io/guides/asking-questions/

### How to submit

1. In your fork of the coursework repo, checkout the main branch
2. Make a new branch from main called `coursework/sprint-3-practice-tdd`
3. Make regular small commits in this branch with clear messages.
4. When you are ready, open a PR to the CYF repo, following the instructions in the PR template.

There are several directories in this repo. [Make a new branch](https://simpledev.io/lesson/create-branch-gh-desktop-1) for each issue in each sprint. Only change files in the `Sprint-3/2-practice-tdd` directory.