fixed rendering bug on show page
refactored percent_discounts to be more readable
- simplified and removed unnecessary calls
- Implemented instance method to calculate percent off
Further Simplify Class
Remove unused implementation method
refactored average price for clarity
seperated unlike concerns
removed duplication of code
extracted price log concerns into price log
merged refactoring of product model

Signed-off-by: Steve Magelowitz <steven.magelowitz@gmail.com>