Update VERSION and XOS parent container

Change-Id: I792cac35b8c06ff46f1d898e80b6268506c85702
diff --git a/Dockerfile b/Dockerfile
index dd21566..9fa0c46 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 # docker build -t xosproject/xos-tosca:candidate .
 
 # xosproject/xos-tosca
-FROM xosproject/xos-client:master
+FROM xosproject/xos-client:2.1.12
 
 # Set environment variables
 ENV CODE_SOURCE .