Send json version of a contact to content store

As part of the architecture change we need to begin sending data to the content-store. This change allows contacts app to send an updated/new contact to the content-store when saving.

The contact is converted to the JSON format expected by the content-store.
:+1: The `.should` syntax is being gradually deprecated in RSpec 3 - https://www.relishapp.com/rspec/rspec-expectations/docs/syntax-configuration