As a user, I want to log in

[alpalma95]

• Implement login logic. See https://github.com/alpalma95/authentication-with-flask-and-react as reference

[alpalma95]

Access token is now generated if email or username match the password.

@sardinhas12 @Jules-11 For the front end form implementation: Please mind that we'll be using the following json structure, for either email or username. Reasoning behind is that we'll need to have just one input valid for entering email and username. The backend will look for the user based on the provided credentials, but always under key "email"

In this case, the provided value for key "email" is username, but test1@testmail.com would produce the same result