* Add requestId to Client context
* Get requestId from req.hull.requestId if not present in config
* Prepare for release 0.13.6
* upgrade hull-client to v1.1.4
* fetch requestId from SNS message-id if available
* Fix client-middleware test
* Adding README section about req.hull.requestId
* simplify requestId lookup in req.hull.requestId
* Simplify requestId flow
* Gettings requestId from X-Hull-Request-Id header for smart notifier
* guard agains undefined req.headers
* Add requestId specs for client middleware