Added script for backing up the live MongoDB.

Assumes you have an SSH tunnel to cloudapi.blender.org with
localhost:27018 forwarded to localhost-at-other-side:27017, like:

	ssh cloudapi.blender.org -L 27018:localhost:27017

backup-db.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+mongodump -h localhost:27018 -d eve --out dump/$(date +'%Y-%m-%d-%H%M') --excludeCollection tokens