SCT-12 Creates the SCSt sink that can launch tasks.

resolves  spring-cloud/spring-cloud-task#12

spring-cloud-task-docs/src/main/asciidoc/features.adoc

@@ -209,3 +209,53 @@ marking the final state of the task.
 }
 ```
 
+=== Launching a task from a Spring Cloud Stream
+
+Allows a user to launch tasks from a stream.  This is done by creating a sink that
+listens for a message that contains a `TaskLaunchRequest` as its payload.  The
+TaskLaunchRequest contains the maven coordinates to the Task that is to be executed.  It
+also has a Map that contains the environment variables that will be used by the Task.
+
+NOTE: If the payload is of a different type then the sink will throw an exception.
+
+For example  a stream can be created that has a processor that takes in data from a
+http source and creates a `GenericMessage` that contains the `TaskLaunchRequest` and sends
+the message to its output channel. The task sink would then receive the message from its
+input channnel and then launch the task.
+
+To create a taskSink a user needs to only create a spring boot app that includes the
+following annotation `EnableTaskLauncher`.  The code would look something like this:
+
+```
+@SpringBootApplication
+@EnableTaskLauncher
+public class TaskSinkApplication {
+	public static void main(String[] args) {
+		SpringApplication.run(TaskSinkApplication.class, args);
+	}
+}
+```
+
+A sample Sink and Processor have been made available to you in the samples module
+of the Spring Cloud Task project.  To install these samples into your local maven
+repository execute a maven build from the `spring-cloud-task-samples` directory with the
+property `skipInstall` set to false.  For example:
+`mvn clean install -DskipInstall=false`.
+
+
+==== Spring Cloud Data Flow
+
+To create a stream in Spring Cloud Data Flow first we would want to register the Task Sink
+Application we created.  In the example below we are registering the Processor and Sink
+sample applications using the Spring Cloud Data Flow shell:
+
+```
+module register --name taskSink --type sink --coordinates io.spring:tasksink:1.0.0.BUILD-SNAPSHOT
+module register --name taskProcessor --type processor --coordinates io.spring:taskprocessor:1.0.0.BUILD-SNAPSHOT
+```
+
+To create a stream from the Spring Cloud Data Flow shell would look like this:
+
+```
+stream create foo --definition "http --server.port=9000|taskProcessor|taskSink" --deploy
+```