Description

Cleaning up the code and making it more readable and concise

Fixes # 3

Type of change

[ ] Import library moved to the top of the code file
[ ] moved variable locations when they are used to make it more readable
[ ] made additional functions for total spent and updating items sold because will be both used in with customers that have customer ids and have no customer ids
[ ] Bug fixed for conditional statements if there is no items purchased or reward points
[ ] Bug fixed for taking inventory of items purchased (counting their numbers and prices]
[ ] Bug fixed for conditional statements if amounts spend is bigger than the rewards cutoff
[ ] added more comments
[ ] added constant variables and removed any numbers hard coded