bring back oslo_clean

oslo_clean is still needed at this point, removing it was
premature, especially for upgrade testing.

Change-Id: Ic845d835f587923423f83ac698bd825f3fa5dd1f
diff --git a/clean.sh b/clean.sh
index f3b2a99..3707d84 100755
--- a/clean.sh
+++ b/clean.sh
@@ -40,6 +40,7 @@
 
 source $TOP_DIR/lib/tls
 
+source $TOP_DIR/lib/oslo
 source $TOP_DIR/lib/horizon
 source $TOP_DIR/lib/keystone
 source $TOP_DIR/lib/glance
@@ -83,6 +84,7 @@
 fi
 
 # Clean projects
+cleanup_oslo
 cleanup_cinder
 cleanup_glance
 cleanup_keystone