Upgrade Kotlin to 1.2.40

build.gradle

@@ -14,7 +14,7 @@ buildscript {
 plugins {
 	id "com.gradle.build-scan" version "1.8"
 	id "io.spring.dependency-management" version "1.0.3.RELEASE" apply false
-	id "org.jetbrains.kotlin.jvm" version "1.2.31" apply false
+	id "org.jetbrains.kotlin.jvm" version "1.2.40" apply false
 	id "org.jetbrains.dokka" version "0.9.16"
 	id "org.asciidoctor.convert" version "1.5.6"
 }
@@ -50,7 +50,7 @@ configure(allprojects) { project ->
 	ext.junitPlatformVersion = "1.1.1"
 	ext.junitJupiterVersion  = "5.1.1"
 	ext.junitVintageVersion  = "5.1.1"
-	ext.kotlinVersion        = "1.2.31"
+	ext.kotlinVersion        = "1.2.40"
 	ext.log4jVersion         = "2.11.0"
 	ext.nettyVersion         = "4.1.24.Final"
 	ext.reactorVersion       = "Californium-BUILD-SNAPSHOT"