when getting product cost the vending machine will now default the cost value to zero if no products found

get product cost will return value when not null

get product cost will return a default value of zero

refactored validation function out of vending machine controller

updated project to use the exception pattern for non success responses

removed superfluous interface for database connection

forgot to add new h2 properties files for tests

cut over to using h2 in memory database for tests

cleaned up unnecessary code

end to end tests will now clean up after themselves investigate in memory db

refactored out unncessary base class for step files

added database tests to ensure we can also delete items from database

added test to validate we can batch insert products into database

renamed feature and step files

added end to end test to validate that I am able to purchase a product from the vending machine