make api compatible with 5.3
make api compatible with 5.3

cesarsmaniotto/arangodb-php,arangodb/arangodb-php,diabl0/arangodb-php,frankmayer/ArangoDB-PHP,frankmayer/ArangoDB-PHP,cesarsmaniotto/arangodb-php,arangodb/arangodb-php,diabl0/arangodb-php