VOL-595 - container image name consistency and general cleanup

Change-Id: Iccac1ccba61537cefa046118df139196e9e87713
diff --git a/compose/docker-compose-opennms.yml b/compose/docker-compose-opennms.yml
index d1dbcb6..fe9b349 100644
--- a/compose/docker-compose-opennms.yml
+++ b/compose/docker-compose-opennms.yml
@@ -1,12 +1,12 @@
 version: '2'
 services:
   database_data:
-    image: tianon/true
+    image: "${REGISTRY}tianon/true:${TRUE_TAG:-latest}"
     volumes:
         - /var/lib/postgresql/data
 
   database:
-    image: postgres:9.6.1
+    image: "${REGISTRY}postgres:${POSTGRES_TAG:-9.6.1}"
     env_file:
       - ./opennms/env/postgres.env
     ports:
@@ -17,14 +17,14 @@
       - database_data:rw
 
   opennms_data:
-    image: tianon/true
+    image: "${REGISTRY}tianon/true:${TRUE_TAG:-latest}"
     volumes:
       - /var/log/opennms
       - /var/opennms/rrd
       - /var/opennms/reports
 
   opennms:
-    image: cord/opennms
+    image: "${REGISTRY}voltha/opennms:${TAG:-latest}"
     env_file:
       - ./opennms/env/opennms.env
       - ./opennms/env/postgres.env