Allow users to set extra client options when needed (logging for example)

I had/have some problems with getting my environment to work with elasticsearch, and one of the latest problems i had was that for some reason elastica returns that all shards have failed, while all shards are in fact green.

So I wanted to enable logging on elastica (i know this requires the psr/log package, but i handle this in my own composer.json). To do so now, would require changing the plugin, which i rather not, so I thought i'd submit this filter addition