Merge pull request spring-projects#11016 from sdeleuze:kotlin-1.1.60

* pr/11016:
  Upgrade to Kotlin 1.1.60

Author: snicoll

spring-boot-project/spring-boot-dependencies/pom.xml

@@ -105,7 +105,7 @@
 		<junit.version>4.12</junit.version>
 		<junit-jupiter.version>5.0.2</junit-jupiter.version>
 		<junit-platform.version>1.0.2</junit-platform.version>
-		<kotlin.version>1.1.51</kotlin.version>
+		<kotlin.version>1.1.60</kotlin.version>
 		<lettuce.version>5.0.0.RELEASE</lettuce.version>
 		<liquibase.version>3.5.3</liquibase.version>
 		<log4j2.version>2.9.1</log4j2.version>