After cloning the repo and running: `docker build -t localstack:latest .`
I can see the following errors:

```
Starting mock Lambda service (http port 4574)...
ERROR: Error forwarding request: HTTPConnectionPool(host='127.0.0.1', port=4564): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f4c7b4e7c10>: Failed to establish a new connection: [Errno 111] Connection refused',)) Traceback (most recent call last):
  File "/opt/code/localstack/localstack/services/generic_proxy.py", line 216, in forward
    headers=forward_headers, stream=True)
  File "/opt/code/localstack/.venv/lib/python2.7/site-packages/requests/api.py", line 116, in post
    return request('post', url, data=data, json=json, **kwargs)
  File "/opt/code/localstack/.venv/lib/python2.7/site-packages/requests/api.py", line 60, in request
    return session.request(method=method, url=url, **kwargs)
  File "/opt/code/localstack/.venv/lib/python2.7/site-packages/requests/sessions.py", line 524, in request
    resp = self.send(prep, **send_kwargs)
  File "/opt/code/localstack/.venv/lib/python2.7/site-packages/requests/sessions.py", line 637, in send
    r = adapter.send(request, **kwargs)
  File "/opt/code/localstack/.venv/lib/python2.7/site-packages/requests/adapters.py", line 516, in send
    raise ConnectionError(e, request=request)
ConnectionError: HTTPConnectionPool(host='127.0.0.1', port=4564): Max retries exceeded with url: / (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f4c7b4e7c10>: Failed to establish a new connection: [Errno 111] Connection refused',))
```

I see the same thing when running `localstack start --docker` which is what I originally tried as I would like to use localstack for development purposes in an existing stack.

MacOS Mojave 10.14
Docker for Mac: 18.06.1-ce-mac73 (26764)
for entry in port_ranges)
    if services:
        port_mappings = ''
        for service, port in service_ports.items():
            port_mappings += ' -p {port}:{port}'.format(port=port)
    env_str = ''
    for env_var in config.CONFIG_ENV_VARS:
        value = os.environ.get(env_var, None)
        if value is not None:
            env_str += '-e %s="%s" ' % (env_var, value)
    data_dir_mount = ''
    data_dir = os.environ.get('DATA_DIR', None)
    if data_dir is not None:
        container_data_dir = '/tmp/localstack_data'
        data_dir_mount = '-v "%s:%s" ' % (data_dir, container_data_dir)
        env_str += '-e DATA_DIR="%s" ' % container_data_dir
    interactive = '' if force_noninteractive or in_ci() else '-it '
    
    entrypoint = '%s ' % entrypoint if entrypoint else entrypoint
    plugin_run_params = '%s ' % plugin_run_params if plugin_run_params else plugin_run_params
    docker_cmd = ('docker run %s%s%s%s' +
        '-p 8080:8080 %s %s' +
        '-v "%s:/tmp/localstack" -v "%s:%s" ' +
        '-e DOCKER_HOST="unix://%s" ' +
        '-e HOST_TMP_FOLDER="%s" "%s" %s') % (
            interactive, entrypoint, env_str, plugin_run_params, port_mappings, data_dir_mount,
            config.TMP_FOLDER, config.DOCKER_SOCK, config.DOCKER_SOCK, config.DOCKER_SOCK,
            config.HOST_TMP_FOLDER, image_name, cmd
    )
    mkdir(config.TMP_FOLDER)