Add shopping svc
Create orders table
Create purchases table
Create payments table
Create payment methods table
Create addresses table
Fix a few indexes
Rename Customer to User
Rename Order to Purchase, Purchase to Order
Remove self
Revert "Remove self"

This reverts commit aeb587695ac5c00334d828945bc111770a58852a.
Use self when necessary
delete! deactivate! activate! should only work on persisted records
Update spec
Minor style changes