User Story 36, Merchant Dashboard Statistics

[memcmahon]

As a merchant
When I visit my dashboard, I see an area with statistics:
- top 5 items I have sold by quantity, and the quantity of each that I've sold
- total quantity of items I've sold, and as a percentage against my sold units plus remaining inventory (eg, if I have sold 1,000 things and still have 9,000 things in inventory, the message would say something like "Sold 1,000 items, which is 10% of your total inventory")
- top 3 states where my items were shipped, and their quantities
- top 3 city/state where my items were shipped, and their quantities (Springfield, MI should not be grouped with Springfield, CO)
- name of the user with the most orders from me (pick one if there's a tie), and number of orders
- name of the user who bought the most total items from me (pick one if there's a tie), and the total quantity
- top 3 users who have spent the most money on my items, and the total amount they've spent

DO THESE STORIES FIRST:

• User Story 34, Merchant Dashboard Show Page

Checklist:

• base tests are written
• base code is written to pass tests
• edge case ("sad path") tests written (if required)
• edge case code written (if required)
• code is reviewed
• branch is merged
• all tests still pass

child of turingschool-projects#233

child of turingschool-projects#274

depends on turingschool-projects#232