XD-2516 Environment and servers.yml properties are ignored for Rabbit

Use Spring Boot's externalized configuration support for populating the `RabbitProperties` bean.
XD-2510 Add spring-integration-amqp as a dependency for both Rabbit sink and source

Fix redis sink dependencies
XD-2122: Use roles for security access
XD-2518 Upgrade to Gradle 2.2
XD-2496 - Refactor use of getContainerHostForSource in integration tests

* Created ContainerResolver for looking up runtime location of a module.
* Added httpSource and other xyzSource methods that take a stream name.
* Updated assertReceived to assertReceivedBySink/Source/Processor.
Updated code based on code review.
Show 'asciidoctorHtml' when executing `./gradlew tasks`