Refactoring - Chapter 1 - 05 - 1 -Moved the amount calculation to Rental class
Refactoring - Chapter 1 - 05 - 2 - Elimimated mountFor() method.
Refactoring - Chapter 1 - 06 - Replaced Temp with Query [amount by rental.getCharge()]
Refactoring - Chapter 1 - 07 - 1 - Extract method to isolate the frequent renter points calculation
Refactoring - Chapter 1 - 07 - 2 - Extract method to isolate the frequent renter points calculation