return stack_name in outputs

Change-Id: I923998f661b46c761f0cfe733478198af4134c67
diff --git a/cloud-deploy-pipeline.groovy b/cloud-deploy-pipeline.groovy
index 3c8846c..f432c16 100644
--- a/cloud-deploy-pipeline.groovy
+++ b/cloud-deploy-pipeline.groovy
@@ -112,6 +112,7 @@
 
                 // no underscore in STACK_NAME
                 STACK_NAME = STACK_NAME.replaceAll('_', '-')
+                outputs.put('stack_name', STACK_NAME)
 
                 // set description
                 currentBuild.description = "${STACK_NAME}"
@@ -194,6 +195,7 @@
 
                 // set description
                 currentBuild.description = STACK_NAME
+                outputs.put('stack_name', STACK_NAME)
 
                 if (STACK_REUSE.toBoolean() == false) {
                     // get templates