Add POJO sample and switch to using that for testing

spring-cloud-function-context/pom.xml

@@ -26,6 +26,10 @@
 			<artifactId>spring-cloud-function-core</artifactId>
 			<version>${spring-cloud-function.version}</version>
 		</dependency>
+		<dependency>
+			<groupId>com.fasterxml.jackson.core</groupId>
+			<artifactId>jackson-databind</artifactId>
+		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-configuration-processor</artifactId>