return_tuple in conn.insert/replace/store does not work

Please add `return` to `conn.insert`, `conn.replace` and `conn.store`

```
    def replace(self, space_name, values, return_tuple=None):
..
        -->> return self._insert(space_name, values, (
            BOX_RETURN_TUPLE if return_tuple else 0) | BOX_REPLACE)
```
