Expose user data to ElasticSearch about wunderhub

[mikebell]

Using search API and search seems overkill. wkhub_search relies on search so that might have to be re-worked if this is the right solution.

[mikebell]

Seems like both search_api_elasticsearch and elasticsearch_connector are both immature.

• search_api_elasticsearch - dependency hell, requires version of search_api that doesn't exist
• elasticsearch - https://www.drupal.org/node/2653628

[danielnolde]

If still relevant: @floretan has done some work integrating Elastisearch with Drupal 8, using the standard Elasticsearch PHP library, with good outcomes.