Intial commit

This includes the Rails project skeleton, extra gems for the project, and the following models:

* Purchaser
* Merchant
* Purchased Items
* Uploads

I considered adding an "Item" model to normalize the items in the example file, but as I looked at the sample data, I decided against it. This was because the new company's item descriptions includes pricing, which means a change in price will trigger a new item being created. I would want to work the company to change the way they store item descriptions, or find a way to clean this data before importing.
Add UploadParser

This class takes a string that contains the contents of a tab-separated value file and parses it. It will be used in the Upload controller.
Set up Upload controller

This provides the functionality for the controller to receive and parse uploaded files.
Create file upload form

This provides the upload form to be used when uploading a file.
Add calculation for total gross revenue

This adds a method to the Upload model to calculate the total gross revenue. It also displays that amount on the 'show' page in order to meet that requirement.