We are adding hook handlers and some improved integration for Wikibase content in CirrusSearch.
For jenkins to actually run tests for this, we need to add CirrusSearch and Elastica extensions as dependencies.
these should be optional dependencies for running wikibase itself (e.g. only if CirrusSearch is installed and $wgSearchType or alternatives includes Cirrus then use the enhanced search capabilities), but we still need the dependencies for full testing
afaik, we don't need ElasticSearch itself (yet) since Elastica provides enough abstraction. We'll need to think how we might want to implement some integration tests, but think that's a separate task.