VOL-612 - rename images to work better with public repository

Change-Id: I9679544987c3a08d0001928cfbc39d710a6c1eae
diff --git a/docker/Dockerfile.tools b/docker/Dockerfile.tools
index 168ffee..dfc3e9d 100755
--- a/docker/Dockerfile.tools
+++ b/docker/Dockerfile.tools
@@ -12,8 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 ARG TAG=latest
+ARG REGISTRY=
+ARG REPOSITORY=
 
-FROM voltha/voltha-base:${TAG}
+FROM ${REGISTRY}${REPOSITORY}voltha-base:${TAG}
 
 MAINTAINER Sergio Slobodrian <sslobodr@ciena.com>