clone tempest if enabled

add auto cloning of the tempest tree if it's an enabled service
just reduces one step in getting tempest up in a new environment

Change-Id: Ia8a2feee96f26dffe96c87d572a31735d90cdabb
diff --git a/stack.sh b/stack.sh
index 118c2ef..957bbd6 100755
--- a/stack.sh
+++ b/stack.sh
@@ -313,6 +313,7 @@
 source $TOP_DIR/lib/ceilometer
 source $TOP_DIR/lib/heat
 source $TOP_DIR/lib/quantum
+source $TOP_DIR/lib/tempest
 
 # Set the destination directories for OpenStack projects
 HORIZON_DIR=$DEST/horizon
@@ -871,6 +872,9 @@
 if is_service_enabled ceilometer; then
     install_ceilometer
 fi
+if is_service_enabled tempest; then
+    install_tempest
+fi
 
 
 # Initialization
@@ -917,6 +921,9 @@
 if is_service_enabled cinder; then
     configure_cinder
 fi
+if is_service_enabled tempest; then
+    configure_tempest
+fi
 
 if [[ $TRACK_DEPENDS = True ]] ; then
     $DEST/.venv/bin/pip freeze > $DEST/requires-post-pip