Start 1.3.0: socket.gaierror: [Errno -2] Name or service not known

```
$ sudo docker run -p 8888:8888 beakerx/beakerx:1.3.0
Execute the command
[I 04:52:15.827 NotebookApp] Writing notebook server cookie secret to /home/beakerx/.local/share/jupyter/runtime/notebook_cookie_secret
Traceback (most recent call last):
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/traitlets/traitlets.py", line 528, in get
value = obj._trait_values[self.name]
KeyError: 'allow_remote_access'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 869, in _default_allow_remote
addr = ipaddress.ip_address(self.ip)
File "/opt/conda/envs/beakerx/lib/python3.7/ipaddress.py", line 54, in ip_address
address)
ValueError: '' does not appear to be an IPv4 or IPv6 address

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/opt/conda/envs/beakerx/bin/jupyter-notebook", line 11, in
sys.exit(main())
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/jupyter_core/application.py", line 266, in launch_instance
return super(JupyterApp, cls).launch_instance(argv=argv, **kwargs)
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/traitlets/config/application.py", line 657, in launch_instance
app.initialize(argv)
File "", line 2, in initialize
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/traitlets/config/application.py", line 87, in catch_config_error
return method(app, *args, **kwargs)
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 1629, in initialize
self.init_webapp()
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 1379, in init_webapp
self.jinja_environment_options,
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 158, in __init__
default_url, settings_overrides, jinja_env_options)
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 251, in init_settings
allow_remote_access=jupyter_app.allow_remote_access,
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/traitlets/traitlets.py", line 556, in __get__
return self.get(obj, cls)
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/traitlets/traitlets.py", line 535, in get
value = self._validate(obj, dynamic_default())
File "/opt/conda/envs/beakerx/lib/python3.7/site-packages/notebook/notebookapp.py", line 872, in _default_allow_remote
for info in socket.getaddrinfo(self.ip, self.port, 0, socket.SOCK_STREAM):
File "/opt/conda/envs/beakerx/lib/python3.7/socket.py", line 748, in getaddrinfo
for res in _socket.getaddrinfo(host, port, family, type, proto, flags):
socket.gaierror: [Errno -2] Name or service not known
```

Reproduce the failure with the reported Docker command, then start at notebook/notebookapp.py and follow the empty self.ip path through socket.getaddrinfo. Done means the beakerx/beakerx:1.3.0 container starts its Jupyter notebook server without the socket.gaierror.

Written by the indexing model from the issue text.