RestartContainerTest.test_restart_with_low_timeout Test failing on initial development build

Hi all!

I'm trying to build an editable installation, and I'm getting failures when trying to run the test suite. Here are some stats on my system.

Running Mac OS X 10.13.4 with:

pip freeze | grep docker && python --version && docker version

51:-e git+https://github.com/wsavran/docker-py.git@b3d2e54a2df32c0758814d764454dd2a2c0ca3c2#egg=docker
52:docker-pycreds==0.3.0
Python 3.6.3 :: Anaconda custom (64-bit)
Client:
 Version:      18.03.1-ce
 API version:  1.37
 Go version:   go1.9.5
 Git commit:   9ee9f40
 Built:        Thu Apr 26 07:13:02 2018
 OS/Arch:      darwin/amd64
 Experimental: false
 Orchestrator: swarm

Server:
 Engine:
  Version:      18.03.1-ce
  API version:  1.37 (minimum version 1.12)
  Go version:   go1.9.5
  Git commit:   9ee9f40
  Built:        Thu Apr 26 07:22:38 2018
  OS/Arch:      linux/amd64
  Experimental: true

Here is the output of the failed test:

tests/integration/api_container_test.py:1171: in test_restart_with_low_timeout
    self.client.restart(container, timeout=3)
docker/utils/decorators.py:19: in wrapped
    return f(self, resource_id, *args, **kwargs)
docker/api/container.py:1027: in restart
    res = self._post(url, params=params, timeout=conn_timeout)
docker/utils/decorators.py:46: in inner
    return f(self, *args, **kwargs)
docker/api/client.py:194: in _post
    return self.post(url, **self._set_request_timeout(kwargs))
/usr/local/lib/python2.7/site-packages/requests/sessions.py:565: in post
    return self.request('POST', url, data=data, json=json, **kwargs)
/usr/local/lib/python2.7/site-packages/requests/sessions.py:518: in request
    resp = self.send(prep, **send_kwargs)
/usr/local/lib/python2.7/site-packages/requests/sessions.py:639: in send
    r = adapter.send(request, **kwargs)
/usr/local/lib/python2.7/site-packages/requests/adapters.py:514: in send
    raise ReadTimeout(e, request=request)
E   ReadTimeout: HTTPConnectionPool(host='dpy-dind-py2', port=2375): Read timed out. (read timeout=4)

I tried running a Python2 virtual env and received the same error. Maybe I'm missing something obvious?

Start with tests/integration/api_container_test.py at test_restart_with_low_timeout and trace the call through docker/api/container.py:restart. Reproduce the ReadTimeout using the reported Python, Docker, and macOS setup, then identify why the restart request exceeds the timeout; done means the test completes successfully.