Disable _ttl for ES indexes

[oguzhanunlu]

Elasticsearch 1.7 isn't maintained anymore and there are bug discussions around _timestamp and _ttl.

Upgrading ES to a modern version will prevent most of the headaches coming from not maintained old version. Until then, let's disable _ttl.

[jbeemster]

Hey @oguzhanunlu whats the plan to manage the document age in lieu of having a _ttl? We probably still want to enforce expiration of documents to prevent the mini from filling up.

[oguzhanunlu]

@jbeemster right, curator might be an option.

[oguzhanunlu]

This is handled as part of dockerization sp mini, see #23 .