switch to Groovy DSL

cli/build.gradle

@@ -0,0 +1,42 @@
+plugins {
+    id "org.jetbrains.kotlin.jvm"
+    id "application"
+}
+
+import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+
+dependencies {
+    implementation group:"org.jetbrains.kotlin", name: "kotlin-stdlib-jdk8", version: getProperty("kotlin.version")
+
+    implementation group: "org.apache.logging.log4j", name: "log4j-slf4j-impl", version: property("log4j.version")
+    implementation group: "org.slf4j", name: "slf4j-api", version: property("slf4j.version")
+    implementation group: "com.beust", name: "jcommander", version: property("jcommander.version")
+    implementation rootProject
+
+    testRuntimeOnly group: "org.junit.jupiter", name: "junit-jupiter-engine", version: property("junit.version")
+    testImplementation group: "org.junit.jupiter", name: "junit-jupiter-api", version: property("junit.version")
+    testImplementation group: "org.junit.jupiter", name: "junit-jupiter-params", version: property("junit.version")
+}
+
+application {
+    mainClassName = "net.woggioni.jzstd.Cli"
+}
+
+
+tasks.withType(Test) {
+    useJUnitPlatform()
+}
+
+java {
+    sourceCompatibility = JavaVersion.VERSION_1_8
+    targetCompatibility = JavaVersion.VERSION_1_8
+}
+
+tasks.withType(KotlinCompile.class).configureEach {
+    kotlinOptions {
+        languageVersion = "1.5"
+        apiVersion = "1.5"
+        jvmTarget = "1.8"
+        javaParameters = true
+    }
+}