Upgrade to Kotlin 1.2
Upgrade to Kotlin 1.2

apiVersion and languageVersion options are set to 1.1
on production code in order to avoid incompatibilities
with Kotlin 1.1 based projects or libraries.

Issue: SPR-16239

spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework,spring-projects/spring-framework