Merge branch 'upgrade-kotlin' into 'sprint'

Upgrade Kotlin to 1.2.60

See merge request open-platform/api!206

Author: Ruslan Molchanov

build.gradle

@@ -1,10 +1,10 @@
 plugins {
     id 'jacoco'
     id "idea"
-    id "org.jetbrains.kotlin.jvm" version "1.2.51"
-    id "org.jetbrains.kotlin.kapt" version "1.2.51"
-    id "org.jetbrains.kotlin.plugin.spring" version "1.2.51"
-    id "org.jetbrains.kotlin.plugin.jpa" version "1.2.51"
+    id "org.jetbrains.kotlin.jvm" version "1.2.60"
+    id "org.jetbrains.kotlin.kapt" version "1.2.60"
+    id "org.jetbrains.kotlin.plugin.spring" version "1.2.60"
+    id "org.jetbrains.kotlin.plugin.jpa" version "1.2.60"
     id "org.springframework.boot" version "2.0.4.RELEASE"
 }