Upgrade versions; prepare for release

Author: garyrussell

build.gradle

@@ -61,14 +61,14 @@ ext {
 	junitJupiterVersion = '5.7.2'
 	kafkaVersion = '3.0.0'
 	log4jVersion = '2.14.1'
-	micrometerVersion = '1.8.0-M3'
+	micrometerVersion = '1.8.0-RC1'
 	mockitoVersion = '3.11.2'
-	reactorVersion = '2020.0.11'
+	reactorVersion = '2020.0.12'
 	scalaVersion = '2.13'
-	springBootVersion = '2.5.4' // docs module
-	springDataVersion = '2021.1.0-M3'
+	springBootVersion = '2.5.5' // docs module
+	springDataVersion = '2021.1.0-RC1'
 	springRetryVersion = '1.3.1'
-	springVersion = '5.3.10'
+	springVersion = '5.3.11'
 	zookeeperVersion = '3.6.3'
 
 	idPrefix = 'kafka'