update item and transaction to return successful methods
WIP, getting all the ducks in a row with notes included to have delegated methods for most_revenue
complete inplementation of invoice_item#revenue including check for revenue
finish up invoice#invoice_revenue work
first implementation of merchantRepo#most_revenue(x)
add memoization to sales_engine
get merchant_repo#most_revenue passing local tests
get item_repo#most_items working
Get merchant_repo#most_items working