Upgrade versions; prepare for milestone release

Author: garyrussell

build.gradle

@@ -66,11 +66,11 @@ ext {
 	junitJupiterVersion = '5.8.2'
 	kafkaVersion = '3.1.0'
 	log4jVersion = '2.17.1'
-	micrometerVersion = '2.0.0-M1'
+	micrometerVersion = '2.0.0-M2'
 	mockitoVersion = '4.0.0'
-	reactorVersion = '2020.0.15'
+	reactorVersion = '2020.0.16'
 	scalaVersion = '2.13'
-	springBootVersion = '2.6.2' // docs module
+	springBootVersion = '2.6.3' // docs module
 	springDataVersion = '2022.0.0-M1'
 	springRetryVersion = '1.3.1'
 	springVersion = '6.0.0-M2'