added multi-release-jar plugin

dependency-export/build.gradle.kts

@@ -13,9 +13,33 @@ dependencies {
     implementation("org.jetbrains.kotlin:kotlin-stdlib-jdk8")
 }
 
-gradlePlugin {
-    val dependencyExportPlugin by plugins.creating {
-        id = "net.woggioni.plugins.dependency-export"
-        implementationClass = "net.woggioni.plugins.dependency.export.DependencyExportPlugin"
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+arrayOf("apiElements", "runtimeElements").forEach { name : String ->
+    val conf = project.configurations.getByName(name)
+    conf.attributes {
+        attribute(TargetJvmVersion.TARGET_JVM_VERSION_ATTRIBUTE, 8)
     }
 }
+
+
+gradlePlugin {
+    plugins {
+        create("DependencyExportPlugin") {
+            id = "net.woggioni.plugins.dependency-export"
+            implementationClass = "net.woggioni.plugins.dependency.export.DependencyExportPlugin"
+        }
+    }
+}
+
+tasks.withType<org.jetbrains.kotlin.gradle.tasks.KotlinCompile>().configureEach {
+    kotlinOptions {
+        languageVersion = "1.3"
+        apiVersion = "1.3"
+        jvmTarget = "1.8"
+        javaParameters = true   // Useful for reflection.
+    }
+}