User Can Post Product (#76772954)

As discussed, contains basic Rails CRUD for a Product model.

It will validate URLs and names of Products and will clean up extraneous content. 

*Problem:* It is valid to enter two identical URLs in the form of `http://example.com/` and `https://example.com/`. Therefore, the uniqueness property of a product's URL is not actually valid all of the time. I tried fixing it, but the solution was not pretty. (What would be prettier I guess is to double-check for uniqueness. Thoughts?)
attribute_present?() is sufficient: http://apidock.com/rails/ActiveRecord/Base/attribute_present%3F