CORD-1033 Build and publish service synchronizers on corddev

Change-Id: I6bf1054f574c27ebee6276d313a60daf24bf8bce
diff --git a/xos/synchronizer/Dockerfile.synchronizer b/xos/synchronizer/Dockerfile.synchronizer
index e70aad6..5e8144e 100644
--- a/xos/synchronizer/Dockerfile.synchronizer
+++ b/xos/synchronizer/Dockerfile.synchronizer
@@ -1,4 +1,4 @@
-FROM xosproject/xos-synchronizer-base
+FROM xosproject/xos-synchronizer-base:candidate
 
 ADD . /opt/xos/synchronizers/exampleservice