version updated to 1.7
first red test for shelf storage
shelf storage green
test storage with 2 products, red phase
test storage with 2 products, green phase
remove code duplication, prepare shelf refactor
extracted Shelf class, red for tests
fix given state, red test for adding items to shelf
move shelf testing to shelf test class
fix in creating shelf
adding product to shelf red
adding product to shelf green
storage initial red test
storage initial green test, mounting new shelf in storage
storage refactor, add constructor
storage, mount shelf of given product to storage red
storage, mount shelf of given product to storage green
storage refactor
test on exception when you put 2 shelf on same slot red
test on exception when you put 2 shelf on same slot green
refactor shelf test, remove outdated tests