Added Wishlist and Sku mapping classes
Added Address embeddable object
Added Sku entity with ManyToMany relationship with wishlists
Added Wishlist object with ManyToMany relationship with Sku
Refactor - renamed to UserDetails
Refactor - renamed from Users
Added OneToMany relationship with Wishlist, i.e. one user can have many
wishlists
Refactor
Updated to include testing of new objects/entities and their
relationships, i.e. 

Address is embeddable object for UserDetails
UserDetails - OneToMany - Wishlist
Wishlist - ManyToMany - Sku