Meza/Upgrade from Meza 27.x

If you get Elasticsearch errors
Meza is able to update Elasticsearch from Meza 27.x (with MediaWiki 1.27.x) to Meza 30.x (with MediaWiki 1.30.x) through a two-step process of firs upgrading from Elasticsearch 1.6 to 2.x, then upgrading from 2.x to 5.x. This works consistently in testing of smaller wikis, but unfortunately has failed on some larger wikis. If you get Elasticsearch errors you will need to destroy your Elasticsearch indexes and start over.