Convert into single docker image, change volume structure etc

Makefile inconsistent!

dockerbin/launch-cron

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -euo pipefail
+IFS=$'\n\t'
+
+# make parallel citation shut up
+mkdir ~executor/.parallel
+touch ~executor/.parallel/will-cite
+
+# repair ownership
+find /data \! -user executor -exec chown executor:executor {} \;
+
+# run cron
+crond -f
+