sqlite-utils query can now run DML (#120)

* Failing test showing that DML in `sqlite-utils query` doesn't work
* Run `sqlite-utils query` in a transaction so that DML is committed

Thanks, @tsibley!

tests/test_cli.py

@@ -1126,3 +1126,6 @@ def test_query_update(db_path, args, expected):
         cli.cli, [db_path, "update dogs set age = 5 where name = 'Cleo'"] + args
     )
     assert expected == result.output.strip()
+    assert db.execute_returning_dicts("select * from dogs") == [
+        {"id": 1, "age": 5, "name": "Cleo"},
+    ]