CORD-1000 Build and publish XOS images on corddev

Change-Id: Ia82115fc1809de3b662c8c6bf2c3ea200d334c40
diff --git a/xos/gui/Dockerfile b/xos/gui/Dockerfile
index b8a636c..911bd15 100644
--- a/xos/gui/Dockerfile
+++ b/xos/gui/Dockerfile
@@ -1,4 +1,4 @@
-FROM xosproject/xos-gui-extension-builder
+FROM xosproject/xos-gui-extension-builder:candidate
 
 # Set environment vars
 ENV CODE_SOURCE .