decomission Travis CI and fix Scrutinizer

fixed broken Request serialization on Slim 3.10.0

update README.md

fix: admit psr/http-message 1.0.1 and beyond

Refactored namespace for simplicity

Rethought MonitorInterface role, refactored to InspectorInterface

API BC changes:

* removed Verifier::setMaximumDelay($maxDelay) (feature removed)
* removed Verifier::setMonitor(MonitorInterface $monitor)
* modified Verifier::__constructor(MonitorInterface $monitor = null)

Added delay detection capability in Verifier

Added replay detection capability in Verifier

New branch due to non-BC api change. Authenticator

class has been chopped into Calculator, Signer and Verifier.

properly handle missing Signed-Headers header when verifying a signed…

… message

greatly improved the clearness and reliability of AuthenticatorTest

* integrated HttpFoundation requests and responses into the test suite

* minor but significant changes in the serializer algorithm