Upgrade Kotlin plugin to 1.3.31

build.gradle

@@ -11,7 +11,7 @@ buildscript {
 // 3rd party plugin repositories can be configured in settings.gradle
 plugins {
 	id "io.spring.dependency-management" version "1.0.5.RELEASE" apply false
-	id "org.jetbrains.kotlin.jvm" version "1.3.30" apply false
+	id "org.jetbrains.kotlin.jvm" version "1.3.31" apply false
 	id "org.jetbrains.dokka" version "0.9.18"
 	id "org.asciidoctor.convert" version "1.5.8"
 }