added JPMS support

cli/build.gradle

@@ -1,9 +1,10 @@
 plugins {
     id "org.jetbrains.kotlin.jvm"
-    id "application"
+    id "net.woggioni.gradle.envelope"
 }
 
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompile
+import net.woggioni.gradle.envelope.EnvelopeJarTask
 
 dependencies {
     implementation group:"org.jetbrains.kotlin", name: "kotlin-stdlib-jdk8", version: getProperty("kotlin.version")
@@ -12,31 +13,21 @@ dependencies {
     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"
+Provider<EnvelopeJarTask> envelopeJarTaskProvider = tasks.named('envelopeJar', EnvelopeJarTask.class) {
+    mainClass = 'net.woggioni.jzstd.Cli'
 }
 
-
-tasks.withType(Test) {
-    useJUnitPlatform()
-}
-
-java {
-    sourceCompatibility = JavaVersion.VERSION_1_8
-    targetCompatibility = JavaVersion.VERSION_1_8
+tasks.named('envelopeRun', JavaExec) {
+    args = ['--help']
 }
 
 tasks.withType(KotlinCompile.class).configureEach {
     kotlinOptions {
-        languageVersion = "1.5"
-        apiVersion = "1.5"
-        jvmTarget = "1.8"
+        languageVersion = "1.6"
+        apiVersion = "1.6"
+        jvmTarget = "11"
         javaParameters = true
     }
 }