log with bunyan

Per documentation - this just makes that into a node package for convenience.

Install

``shell
npm install elasticsearch-bunyan --save
`

Getting started

$3

https://github.com/trentm/node-bunyan#logchild

`js
var es = require('elasticsearch');
var BunyanLog = require('elasticsearch-bunyan').log;
var bunyan = require('bunyan');
var log = bunyan.createLogger({ name: 'mylogger' });
var client = new es.Client({
bunyan: log.child({foo: 'bar'}),
log: BunyanLog
});
`

$3

`js
var es = require('elasticsearch');
var BunyanLog = require('elasticsearch-bunyan').log;
var client = new es.Client({
bunyan: { name: 'mylogger' },
log: BunyanLog
});
``