Add javafx dependency to the Swing integration

Author: dkhalanskyjb

ui/kotlinx-coroutines-swing/build.gradle

@@ -2,6 +2,16 @@
  * Copyright 2016-2018 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
  */
 
+plugins {
+    id 'org.openjfx.javafxplugin' version '0.0.8'
+}
+
+javafx {
+    version = javafx_version
+    modules = [ 'javafx.controls' ]
+    configuration = 'compile'
+}
+
 dependencies {
     testCompile project(':kotlinx-coroutines-jdk8')
-}
+}