[Code Improvement] Remove dc_ajax_add_cart_test module

Problem/Motivation

dc_ajax_add_cart_test doesn't do anything. It was created earlier to store configs that would be necessary for running the tests. As of now there are no such configs, so it is best that you remove it.

Proposed resolution

Make sure that this is the last thing you do before the stable release of dc_ajax_add_cart. Because, maybe in future the test module will indeed store some test configs.

Remaining tasks

N/A

User interface changes

N/A

API changes

N/A

Data model changes

N/A