Created Class QuizServer()

- Added class that extends UnicastRemoteObject.
- Created a set of Quizzes
- Created a Map of Quiz ID to QuizQuestions
- Created a Map of QuizIS to String[] to hold question, MCQs and
correct answer
- included a variable score

- added getter and setter methods
- addQuiz() allows the set-up client to add a Quiz and give it a random
ID number