User Story 14, Items Index Page

[iandouglas]

As any kind of user on the system
I can visit the items catalog ("/items")
I see all items in the system except disabled items
Each item will display the following information:
- the name of the item
- a small thumbnail image for the item
- the merchant name who sells the item
- how many of the item the merchant has in stock
- the merchant's current price for the item

The item name is a link to that item's show page
The item thumbnail is a link to that item's show page

DO THESE STORIES FIRST:

• User Story 2, Visitor Navigation

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 #257

child of #274

depends on #271