Add comparability with Solarium v3.5

The class layout was refactored in Solarium v3.5, the
`Solarium\Core\Query\Query` was deprecated and replaced with a stub.
Classes of type `Solarium\QueryType\Select\Query\Query` are used
instead. This breaks tests for the type of `query`.  Since both of the
aforementioned classes implement `QueryInterface`, testing for instances
of that interface fixes the bug while maintaining backward
comparability.

SolrDataProvider.php

@@ -7,7 +7,7 @@
 use yii\base\InvalidConfigException;
 use yii\data\BaseDataProvider;
 use yii\di\Instance;
-use Solarium\Core\Query\Query as SolrQuery;
+use Solarium\Core\Query\QueryInterface as SolrQuery;
 use sammaye\solr\Client;
 
 /**
@@ -170,4 +170,4 @@ public function setSort($value)
 			}
 		}
 	}
-}
+}