using multiarch images

postgresql/Dockerfile

@@ -1,4 +1,4 @@
-FROM robinthoni/postgres-backup:9.6
+FROM robinthoni/postgres-backup-multiarch:9.6
 
 RUN rm -rf /var/log/*
 

roundcube/Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:jessie
+FROM robinthoni/debian-multiarch:jessie
 
 # FROM https://github.com/ZHAJOR/Docker-Apache-2.4-Php-5.6-for-Laravel
 MAINTAINER Robin Thoni <robin@rthoni.com>