Latest changes 

- In the config/amqp.yml, there is the environment production added where it is defined an existing exchange and queue.
- Indexes are added
- View is removed
- I've added some validation on message routing key, if i cannot handle a message, it is simply rejected
- Added some logging messages on message reception/acknowledgement/rejection/requeueing
- You can just launch the script/start_warehousebuilder.rb, just change the environment to production for now (no more rake needed in the script/worker as well)