Moved product feed generation to Amazon::MWS::XML::Feed
Keep the product object agnostic about the backend
Inventory data
prototyped routine to upload a feed
Created Amazon::MWS::Uploader stub
Implemented in the module the feed posting
Implemented resuming loop to fetch amazon data.

Right now it doesn't set the success because we're still missing the
price, image, variation feeds
Typo fix
Added price feed + miscellaneous fixes and cleaner output
More verbose output
Pass the marketplace id on feed submission

This avoids to leak in other marketplace when submitting the price.

Unclear why the inventory goes only into one marketplace while the price
seems global.

This caused the price upload to fail because other marketplaces returned
errors.

This change require this change in the client:

https://github.com/melmothx/Amazon-MWS/commit/c5ce2bb91702d9cba59cd189a3c42edaa1b628d9
Implemented image feed output
Implemented variants feed
Changed uploader logic and schema

Simplified the schema and populate the feeds table before starting the
loop.

This way we don't have duplicated informations and the schema is more
flexible because it can accomodate more feeds without the need of extending
it.

Also, the ->upload_feed method is more encapsulated and doesn't need to write
into the job table.
Don't write out feeds for empty jobs

This way, we can reach the success state when the feeds are exausted.
get-orders stub
Prepare the insertion of the order
Insert orderlines
Create user if not present
Added a task column to the schema