feature: Added admin controller and digest auth

Generated controller for admin#index.
Set up and styled footer for to login into admin.
Generated controller for admin::orders.
Created namespaced routing for admin and admin::orders
feature: Added content for admin/index.html.erb

Set up four controller actions, Orders, Customers, Inventory, Issues.
feature: completed view for Admin#index

Added new icon fonts via Flaticon vendor.
Created and styled an admin nav partial.
Incorporated icons into view.
feature: Completed admin page for Orders (CRUD)

Added migration and ShippingAddress model to normalize DB from Customer.
Filled all actions for Admin::Orders controller based on available
routes.
Made basic assocations between Customer and ShippingAddress.
Created and integrated partial to handle Admin::Orders#create and
update actions.
Incorporated Admin::Orders helper in respective controller.
Incorporated flash-hash to handle after destroy messaging.
added Product model instance method to return image sources from S3
feature: eliminated excess routes not currently in use from config/routes.rb
feature: Enhanced client-side web app component

Fixed product showcase_image sizing to be uniform.
Added custom favicon for web app.
Modified seed file to reflect accurate amount of product images.
Added validations to Order, ShippingAddress, and Customer models.
Enhanced forms using flash-hash for validation errors and successful
product purchas:e.
Cleaned up charges#create action by extracting multiple model creation,
validation, and sanitization handling to custom Data class located in
the lib folder.
feature: added link in nav partial for anchor to shop
feature: basic admin setup complete
feature: Adds Admin backend for business

Includes CRUD ability for ShippingAddress, Customer, Issue, Product, and
Order.
Merge pull request #4 from SeharaDesign/Admin

Admin