Write a class Student.
Attributes: name, quiz average, homework average, lab average, final examBehaviors:
1. constructor, which takes the student name as input and always initializes the grades to zero.
2. setQuizAvg, which takes an input and sets the quiz average.
3. setHWAvg, which takes an input and sets the homework average.
4. setLabAvg, which takes an input and sets the lab average.
5. setFinalExam, which takes an input and sets the final exam.
6. grade, which calculates and returns the number grade. (quizzes are 20% of grade, homework is 25% of grade, labs are 30% of grade and the final exam is 25% of the grade).
7. accessors for the attributes.