Update Kotlin plugin (1.3.21->1.3.31)

Author: vbauer

build.gradle

@@ -2,7 +2,7 @@
 plugins {
     id 'java'
     id 'jacoco'
-    id 'org.jetbrains.kotlin.jvm' version '1.3.21'
+    id 'org.jetbrains.kotlin.jvm' version '1.3.31'
     id 'com.github.kt3k.coveralls' version '2.8.2'
     id 'com.github.ben-manes.versions' version '0.21.0'
     id 'ru.vyarus.quality' version '3.4.0'