Client helpers (#1107)

* Added client helpers

* Updated test

* The search helper should return only the documents

* Added code comments

* Fixed bug

* Updated test

* Removed bulkSize and added flushBytes

* Updated test

* Added concurrency

* Updated test

* Added support for 429 handling in the scroll search helper

* Updated test

* Updated stats count

* Updated test

* Fix test

* Use client maxRetries as default

* Updated type definitions

* Refactored bulk helper to be more consistent with the client api

* Updated test

* Improved error handling, added refreshOnCompletion option and forward additinal options to the bulk api

* Updated type definitions

* Updated test

* Fixed test on Node v8

* Updated test

* Added TODO

* Updated docs

* Added Node v8 note

* Updated scripts

* Removed useless files

* Added helpers to integration test

* Fix cli argument position

* Moar fixes

* Test run elasticsearch in github actions

* Use master action version

* Add vm.max_map_count step

* Test new action setup

* Added Configure sysctl limits step

* Updated action to latest version

* Don't run helpers integration test in jenkins

* Run helpers integratino test also with Node v10

* Updated docs

* Updated docs

* Updated helpers type definitions

* Added test for helpers type definitions

* Added license header

docs/examples/bulk.asciidoc

@@ -4,6 +4,8 @@
 The `bulk` API makes it possible to perform many index/delete operations in a 
 single API call. This can greatly increase the indexing speed.
 
+NOTE: Did you know that we provide an helper for sending bulk request? You can find it {jsclient}/client-helpers.html[here].
+
 [source,js]
 ----
 'use strict'