kotlin version updated

Dmitry-Borodin · Dmitry-Borodin · commit b3a7dbc01496 · 2019-05-12T15:49:53.000+02:00
diff --git a/build.gradle b/build.gradle
@@ -2,7 +2,7 @@
 apply plugin: 'kotlin'
 
 buildscript {
-    ext.kotlin_version = '1.3.21'
+    ext.kotlin_version = '1.3.31'
     repositories {
         google()
         jcenter()
