Update parent version for sample

samplecode/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.2.0.RELEASE</version>
+		<version>2.3.0.RELEASE</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>