(cherry picked from commit 8600bf0)

* fixed unit tests to support phpunit 6

* do not use sudo

* update elasticsearch in the travis env and use docker vm

* add java jdk8

* temporary remove elasticsearch scripting

* clean up travis file

* null cannot be used in count() functions anymore in 7.2

* remove deprecated queries

* move tests

* added support for 5.x elasticsearch syntax

changed script_score lang to painless

* refactored tests to support elastic 5

* update changelog

* uri parameters was moved to container, introduced 5.0 new request body parameters

* removed filter endpoint, change order for query and postfilter

* search test has too many not necessary test cases

All those tests has to be in specific query or endpoint. Also functional tests make more sense then asserting it in the SearchTest

* moving elasticsearch/elasticsearch to required dependencies

Fixed bug on nested and reverse nested aggregations. None of these aggregations requires the nested aggregations to be added. Test has also been updated. (#173)

* Moved all tests to Unit folder

* updated travis to install elasticsearch

* updated composer to install elasticsearch

* updated namespace in unit tests

* added funtional tests

* fix match all query composing

When there are no parameters it has to return \stdClass.

(cherry picked from commit 5970e92)

* updated unit test for match all query

* constants can only have underscore dash

* fixed psr style issues

* updated travis

* exclude not compatible versions