Create a test folder and create basic function tests via Pytest

[joelansbro]

It is an essential part of software development to create test functions alongside my code, to ensure that code works correctly. This is also a good thing to do for work,

• Install Pytest, coverage (checks if all functions have tests), and black, pylint for linting practices
• Create a test folder and generate some test functions

This guide will be useful as it covers pytest alongside a flask application: https://testdriven.io/blog/modern-tdd/ So we can run through the practices and then head straight into adding it into our project if we wish