Upgrade to Tomcat 9.0.37, Netty 4.1.51, Checkstyle 8.34

build.gradle

@@ -37,14 +37,14 @@ ext {
 	junit5Version        = "5.3.2"
 	kotlinVersion        = "1.2.71"
 	log4jVersion         = "2.11.2"
-	nettyVersion         = "4.1.50.Final"
+	nettyVersion         = "4.1.51.Final"
 	reactorVersion       = "Californium-BUILD-SNAPSHOT"
 	rxjavaVersion        = "1.3.8"
 	rxjavaAdapterVersion = "1.2.1"
 	rxjava2Version       = "2.2.19"
 	slf4jVersion         = "1.7.30"	  // spring-jcl + consistent 3rd party deps
 	tiles3Version        = "3.0.8"
-	tomcatVersion        = "9.0.36"
+	tomcatVersion        = "9.0.37"
 	undertowVersion      = "2.0.30.Final"
 
 	gradleScriptDir = "${rootProject.projectDir}/gradle"
@@ -142,7 +142,7 @@ configure(allprojects) { project ->
 	}
 
 	checkstyle {
-		toolVersion = "8.33"
+		toolVersion = "8.34"
 		configDir = rootProject.file("src/checkstyle")
 	}