Switch to using *Builders in the native client

[michaelklishin]

ElasticSearch client post 1.0 uses *Builder classes for requests. We should use them where possible (we currently instantiate *Requests directly in most places).

[jqmtor]

Hey @michaelklishin ,

How do you see this change being implemented? The clojurewerkz.elastisch.native.conversion namespace would have a bunch of ->*-builder functions to replace the ->*-request ones?

I've spent some time looking into this but the Elasticsearch docs on the site does not help a lot. I try to see how the previous versions of the Java client worked when compared to the current ones, but sometimes the examples correspond to the current version only (even when I switch to the old ones).

[michaelklishin]

@quimrstorres yup. The conversion functions are not part of the public API, so don't worry about introducing breaking changes. I wouldn't object if this went into 3.0, too.

[jqmtor]

@michaelklishin cool, thanks!