Adding att-workflow image

Change-Id: I4cc232adfae17fd1280d6244b34bf3c868be1afe
diff --git a/developer/docker_images.yml b/developer/docker_images.yml
index 5b74c19..e210b7a 100644
--- a/developer/docker_images.yml
+++ b/developer/docker_images.yml
@@ -260,6 +260,10 @@
     repo: hippie-oss
     dockerfile: "Dockerfile.synchronizer"
 
+  - name: xosproject/att-workflow-driver-synchronizer
+    repo: att-workflow-driver
+    dockerfile: "Dockerfile.synchronizer"
+
   - name: xosproject/xos-api-tester
     repo: cord-tester
     path: "src/test/cord-api"