Functional tests (#166)

* 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