Change the way to delete an item in a certain shopping cart

[TimothyXu]

As a system administrator I need to have a nested shopcarts API So that our microservice can be used intuitively as a RESTful service

Details and Assumptions

• Use DELETE /shopcarts/{id}/items/{id}

• Per prof: 'To be RESTful you must use POST for create, GET for read, PUT for update, and DELETE for delete. So deleting an item is not an update. It is a deletion and should use the proper HTTP verb DELETE.'

  Acceptance Criteria

  Given valid customer_id and item_id
  When we call DELETE on /shopcarts/{customer_id}/items/{item_id}
  Then service returns code 204 NO CONTENT
  And service returns empty message

[TimothyXu]

Per lecture 04 about RESTful services, DELETE needs to be idempotent so in particular, even if {item_id} did not exist, when we call DELETE on it there should be no errors and we should still get 204 DELETED. Further the lecture said delete must always return empty message. Updated above to reflect these.