Update Kotlin versions

Author: elizarov

atomicfu-gradle-plugin/build.gradle

@@ -7,7 +7,13 @@ apply plugin: 'java-gradle-plugin'
 
 apply from: rootProject.file('gradle/compile-options.gradle')
 
-ext.configureKotlin()
+// Gradle plugin must be compiled targeting the same Kotlin version as used by Gradle
+kotlin.sourceSets.all {
+    languageSettings {
+        apiVersion = "1.3"
+        languageVersion = "1.3"
+    }
+}
 
 dependencies {
     compile gradleApi()

gradle/compile-options.gradle

@@ -6,8 +6,8 @@
 ext.configureKotlin = {
     kotlin.sourceSets.all {
         languageSettings {
-            apiVersion = "1.3"
-            languageVersion = "1.3"
+            apiVersion = "1.4"
+            languageVersion = "1.4"
             useExperimentalAnnotation("kotlin.Experimental")
             useExperimentalAnnotation("kotlin.ExperimentalStdlibApi")
         }