User can purchase a Nazarene product on the app

[jwld]

• User can search and filter products (User can search and filter products  #16)
• User can view a seller's profile page (Customer wants to be able to see the seller's profile page #17)
• User can add a product to a shopping cart (User can add a product to a shopping cart #62)
• User can proceed to checkout screen and purchase a product (User can purchase a product on the app #40)
• User receives confirmation after purchasing a product (User receives confirmation after purchasing a product #41)