Return body output after given status reached

This change allows stack output to be parsed/checked.

Partial-Bug: #1269566
Partial blueprint: tempest-heat-integration

Change-Id: Iff23620dbce2c834591836dfed8b68439a9804cf
diff --git a/tempest/services/orchestration/json/orchestration_client.py b/tempest/services/orchestration/json/orchestration_client.py
index 20f1b06..6e89258 100644
--- a/tempest/services/orchestration/json/orchestration_client.py
+++ b/tempest/services/orchestration/json/orchestration_client.py
@@ -175,7 +175,7 @@
             stack_name = body['stack_name']
             stack_status = body['stack_status']
             if stack_status == status:
-                return
+                return body
             if fail_regexp.search(stack_status):
                 raise exceptions.StackBuildErrorException(
                     stack_identifier=stack_identifier,