CORD-2817 remove xos-core steps from Makefile

Change-Id: If81ea302cd5551d3875061244fa73bf506050016
diff --git a/docker_images.yml b/docker_images.yml
index f778b85..09c1ffc 100644
--- a/docker_images.yml
+++ b/docker_images.yml
@@ -68,6 +68,12 @@
     dockerfile: "Dockerfile.xos"
     context: "../.."
 
+  - name: xosproject/xos-ui
+    repo: xos
+    path: "containers/xos"
+    dockerfile: "Dockerfile.UI"
+    context: "../.."
+
   - name: xosproject/xos-libraries
     repo: xos
     path: "containers/xos"