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

Scripted metric type missmatch

Fix notice in BoolQuery::getQueries when nothing is added to bool type

Added a getter for a filter in filter aggregation

# Conflicts:
#	src/Aggregation/CardinalityAggregation.php
#	src/Aggregation/NestedAggregation.php
#	src/Aggregation/ReverseNestedAggregation.php

Fixes nested and reverse nested aggregation requirements

InnerHit new implementation