Elasticsearch backup strategy

[tomjanssens]

We should still look into backing up the Elasticsearch cluster. This is not high prio for now as we can easily rebuild the entire support index using the import script (application/manager/component/support/controller/import.php), only takes a couple of seconds for now.

Instructions: https://www.elasticsearch.org/blog/introducing-snapshot-restore/

Recommended : setup the Knapsack plugin to easily copy data back and forth for testing purposes. See https://github.com/jprante/elasticsearch-knapsack