Empty answers are allowed during a quiz

[imaginarys96]

Description

When doing a quiz, blank answers are allowed. It is possible that a user accidentally hits enter on their keyboard, which might cause them to skip a question.

Steps to Reproduce

1. Run the app
2. Have at least 1 question in the question bank
3. Run start /all /random
4. You will be prompted to enter your answer for the question, hit enter on your keyboard

Expected Output

Should inform the user that the answer is blank and let the user try again

Actual Output

start /all /random
    ____________________________________________________________

    Starting the quiz...
    ____________________________________________________________

    Question 1 / 2:
    represent the fraction 5.3 as a mixed number
  Your Answer:
    Wrong!
    Questions left: 1
    ____________________________________________________________

    Question 2 / 2:
    aaa
  Your Answer:
    Wrong!
    Quiz completed!
    Your score: 0/2
    ____________________________________________________________

Screenshot