(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

* 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