Upgrade versions; prepare for release

Author: garyrussell

build.gradle

@@ -63,12 +63,12 @@ ext {
 	log4jVersion = '2.17.1'
 	micrometerVersion = '1.6.13'
 	mockitoVersion = '3.9.0'
-	reactorVersion = '2020.0.15'
+	reactorVersion = '2020.0.16'
 	scalaVersion = '2.13'
 	springBootVersion = '2.4.13' // docs module
-	springDataVersion = '2021.0.8'
+	springDataVersion = '2021.0.9'
 	springRetryVersion = '1.3.1'
-	springVersion = '5.3.15'
+	springVersion = '5.3.16'
 
 	idPrefix = 'kafka'
 }