Upgrade to Groovy 2.5.9, RxJava 2.2.18, Tomcat 9.0.31, Jetty 9.4.26, Netty 4.1.45, Checkstyle 8.29

Author: jhoeller

build.gradle

@@ -30,21 +30,21 @@ ext {
 
 	aspectjVersion       = "1.9.5"
 	freemarkerVersion    = "2.3.28"
-	groovyVersion        = "2.5.8"
+	groovyVersion        = "2.5.9"
 	hsqldbVersion        = "2.4.1"
 	jackson2Version      = "2.9.9"
-	jettyVersion         = "9.4.25.v20191220"
+	jettyVersion         = "9.4.26.v20200117"
 	junit5Version        = "5.3.2"
 	kotlinVersion        = "1.2.71"
 	log4jVersion         = "2.11.2"
-	nettyVersion         = "4.1.44.Final"
+	nettyVersion         = "4.1.45.Final"
 	reactorVersion       = "Californium-SR16"
 	rxjavaVersion        = "1.3.8"
 	rxjavaAdapterVersion = "1.2.1"
-	rxjava2Version       = "2.2.17"
+	rxjava2Version       = "2.2.18"
 	slf4jVersion         = "1.7.30"	  // spring-jcl + consistent 3rd party deps
 	tiles3Version        = "3.0.8"
-	tomcatVersion        = "9.0.30"
+	tomcatVersion        = "9.0.31"
 	undertowVersion      = "2.0.29.Final"
 
 	gradleScriptDir = "${rootProject.projectDir}/gradle"
@@ -142,7 +142,7 @@ configure(allprojects) { project ->
 	}
 
 	checkstyle {
-		toolVersion = "8.28"
+		toolVersion = "8.29"
 		configDir = rootProject.file("src/checkstyle")
 	}