Some changes for 2018.4.0

Change-Id: I51935b5c555fb962a1e36e1b627ed001ea1afe19
diff --git a/tempest/tempest_ext.conf b/tempest/tempest_ext.conf
index f6e3529..5e33b75 100644
--- a/tempest/tempest_ext.conf
+++ b/tempest/tempest_ext.conf
@@ -1,5 +1,5 @@
 [compute]
-image_ref_alt = ${IMAGE_REF2} 
+image_ref_alt = ${IMAGE_REF2}
 min_microversion = 2.1
 max_microversion = latest
 volume_device_name = vdc