Added geo bounding box filter

Filter/GeoBoundingBoxFilter.php

+<?php
+
+/*
+ * This file is part of the ONGR package.
+ *
+ * (c) NFQ Technologies UAB <info@nfq.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace ONGR\ElasticsearchBundle\DSL\Filter;
+
+use ONGR\ElasticsearchBundle\DSL\BuilderInterface;
+use ONGR\ElasticsearchBundle\DSL\ParametersTrait;
+
+/**
+ * Represents Elasticsearch "Geo Bounding Box" filter.
+ */
+class GeoBoundingBoxFilter implements BuilderInterface
+{
+    use ParametersTrait;
+
+    /**
+     * @var array
+     */
+    private $values;
+
+    /**
+     * @var string
+     */
+    private $field;
+
+    /**
+     * @param string $field
+     * @param array  $values
+     * @param array  $parameters
+     */
+    public function __construct($field, $values, array $parameters = [])
+    {
+        $this->field = $field;
+        $this->values = $values;
+        $this->setParameters($parameters);
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getType()
+    {
+        return 'geo_bounding_box';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function toArray()
+    {
+        if (count($this->values) === 2) {
+            $query = [
+                $this->field => [
+                    'top_left' => $this->values[0],
+                    'bottom_right' => $this->values[1],
+                ],
+            ];
+        } elseif (count($this->values) === 4) {
+            $query = [
+                $this->field => [
+                    'top' => $this->values[0],
+                    'left' => $this->values[1],
+                    'bottom' => $this->values[2],
+                    'right' => $this->values[3],
+                ],
+            ];
+        } else {
+            throw new \LogicException('Geo Bounding Box filter must have 2 or 4 geo points set.');
+        }
+
+        $output = $this->processArray($query);
+
+        return $output;
+    }
+}