Make gradle able to build a jar

Author: kurtisnelson

Lib/build.gradle

@@ -27,5 +27,17 @@ android {
 }
 
 dependencies {
+}
+
+task clearJar(type: Delete) {
+    delete 'build/libs/CardTree.jar'
+}
 
+task makeJar(type: Copy) {
+    from('build/bundles/release/')
+        into('build/libs/')
+    include('classes.jar')
+    rename ('classes.jar', 'CardTree.jar')
 }
+
+makeJar.dependsOn(clearJar, build)