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)
from OpenSSL import crypto
    if os.path.exists(target_file):
        key_file_name = '%s.key' % target_file
        cert_file_name = '%s.crt' % target_file
        return target_file, cert_file_name, key_file_name
    if random and target_file:
        if '.' in target_file:
            target_file = target_file.replace('.', '.%s.' % short_uid(), 1)
        else:
            target_file = '%s.%s' % (target_file, short_uid())
    if target_file and not overwrite and os.path.exists(target_file):
        return
    
    k = crypto.PKey()
    k.generate_key(crypto.TYPE_RSA, 1024)
    
    cert = crypto.X509()
    subj = cert.get_subject()
    subj.C = 'AU'
    subj.ST = 'Some-State'
    subj.L = 'Some-Locality'
    subj.O = 'LocalStack Org'  
    subj.OU = 'Testing'
    subj.CN = 'LocalStack'
    cert.set_serial_number(1000)
    cert.gmtime_adj_notBefore(0)
    cert.gmtime_adj_notAfter(10 * 365 * 24 * 60 * 60)