* Added nexus AddressType
 * Added store flag for sales tax being enabled
 * Updated Address object properties and descriptions
 * Added is_taxable to Product object, POST and PUT routes.
 * Added transaction types for sales tax
 * Added UserFlags for options on user objects
 * Updated Address object (removed auditing fields)
 * Added is_tax_exempt on Order objects
 * Added tax_price on order_item
 * Added store address CRUD routes
 * Updated user address CRUD route docs