In the scope of our work, we're going to introduce PHPUnit by first discussing the User
model, how the authentication method works in Yii, and how it's going to be used in our specific case.
After that, we will sketch our tests to cover all possible uses of the User
class, refactor the model, and then aim to get the test passed.
The current state of the framework that we have installed is not good enough for the features we want to implement.
As underlined in the previous chapters, we're going to follow a TDD approach for this first part.