Incorporates the base image building back into the main repo with multi stage building

docker/docker-prepare.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -e
+
 wait_for_postgres() {
 	attempt_num=1
 	max_attempts=5

docker/install_management_commands.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+set -eu
+
 for command in document_archiver document_exporter document_importer mail_fetcher document_create_classifier document_index document_renamer document_retagger document_thumbnails document_sanity_checker manage_superuser;
 do
 	echo "installing $command..."