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

Change-Id: I9679544987c3a08d0001928cfbc39d710a6c1eae
diff --git a/docker/Dockerfile.tester b/docker/Dockerfile.tester
index a9b1a10..ba7deb9 100644
--- a/docker/Dockerfile.tester
+++ b/docker/Dockerfile.tester
@@ -11,10 +11,11 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # 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 Zsolt Haraszti <zharaszt@ciena.com>
 MAINTAINER Ali Al-Shabibi <ali.al-shabibi@onlab.us>