Replace ElasticSearch with a light weight service.

[dak-x]

ElasticSearch uses a lot of resources, and gives tons of features that are not really used by the service.

Use a lightweight service that only provides the functionality that we require and has a very low memory footprint.

Do explore :

• https://github.com/zhihu/rucene
• https://github.com/blevesearch/bleve