[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

repo2docker/docker.py

@@ -10,11 +10,12 @@
 import tempfile
 from contextlib import contextmanager
 from pathlib import Path
-import docker
 
 from iso8601 import parse_date
 from traitlets import Dict, List, Unicode
 
+import docker
+
 from .engine import Container, ContainerEngine, Image
 from .utils import execute_cmd