Add getQuery Method to FunctionScoreQuery (#271)

* Add getQuery Method to FunctionScoreQuery

Add getQuery Method to FunctionScoreQuery in order to apply changes to query of FunctionScoreQuery.

* Update FunctionScoreQuery.php

src/Query/Compound/FunctionScoreQuery.php

@@ -41,6 +41,16 @@ class FunctionScoreQuery implements BuilderInterface
     {
         $this->query = $query;
         $this->setParameters($parameters);
+    }    
+
+    /**
+     * Returns the query instance.
+     *
+     * @return BuilderInterface object
+     */
+    public function getQuery()
+    {
+        return $this->query;
     }
 
     /**