Supports CTR section of the dataflow.spring.io

resolves another part of #180

It is associated with PR https://github.com/spring-io/dataflow.spring.io/pull/188

transition-sample/Dockerfile

@@ -0,0 +1,7 @@
+FROM java:8-alpine
+
+ARG JAR_FILE
+
+ADD target/${JAR_FILE} taskapp-1.0.0.BUILD-SNAPSHOT.jar
+
+ENTRYPOINT ["java", "-jar", "/taskapp-1.0.0.BUILD-SNAPSHOT.jar"]