Fix most sinatra app specs (run individually ..)

Couldn't make them pass when running them all at once. Still pending
/get_shipments flow
Port get_shipments to wombat patterns
Give a try on fixing some specs

Need to investigate why they all break when the code is loaded at once.
Probably something to do with Ooor bulding the ruby objects from scratch
on every spec
Fix moar param names on orders webhook
Ignore sku in inventory objects

Not really clear what should be an inventory id and inventory sku. For
the time being it considers the inventory id will be the same as the
product
Load SaleOrder model on /get_shipments webhook
Fix health check

@config is not present when doing health check
update unicorn config so it actually runs
Improve get product notification
Add note about creating taxes on the fly
Set SaleOrderLine#tax_id when provided
SaleOrderLine#tax_id needs to receive an array
Use Product#default_code instead of name for mapping

default_code means Internal Reference in OpenERP UI
drop endpoints not ready yet
set up honeybadger