Bump libs up to latest

* Spring Boot 2.6.3
* Spring Cloud 2021.0.0
* SCS/F 3.2.1
* etc..

Partially resolves #156

dataflow-website/stream-developer-guides/streams/standalone-stream-sample/pom.xml

@@ -9,7 +9,7 @@
     <parent>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-parent</artifactId>
-        <version>2.4.2</version>
+        <version>2.6.3</version>
         <relativePath/> <!-- lookup parent from repository -->
     </parent>
 
@@ -22,7 +22,7 @@
         <docker.org>springcloudstream</docker.org>
         <docker.version>${project.version}</docker.version>
         <java.version>1.8</java.version>
-        <spring-cloud.version>2020.0.1</spring-cloud.version>
+        <spring-cloud.version>2021.0.0</spring-cloud.version>
     </properties>
 
     <dependencyManagement>