Add a new method to the worker requestShutdown that allows the worker to
gracefully shutdown all record processors. The graceful shutdown gives
the record processors a last chance to checkpoint before they're
terminated.
To use these new features the record processor must implement
IShutdownnotificationaware.
Added unit tests for many of the classes in the client. Added new
dependencies for the unit tests to the POM file. Unit tests can be
executed the `surefire:test` goal, and are executed during the test phase.
Added integration tests for the client. The tests require access to
credentials that can interact with Kinesis, and DynamoDB. The
integration tests can be run by executing the
`failsafe:integration-test` goal, or are run as part of the
integration-test phase
**Resources in the integration tests are not currently released on
completion of the integration tests.**
