Unable to start the Dashboard server on Windows

Facing socket error when trying to start the `dashboard_server`. Tried on two separate `Windows` environments, but I get the same error.

```
(venv) ausaf@DESKTOP-H6N4CD0 /d/venv/openhtf (master)
λ python -m openhtf.output.servers.dashboard_server --no-launch-web-gui
INFO:__main__:Starting dashboard server at:
Local: http://localhost:12000
Remote: http://DESKTOP-H6N4CD0:12000
INFO:__main__:Starting station discovery.
INFO:__main__:Stopping dashboard server.
Traceback (most recent call last):
File "c:\users\ausaf\appdata\local\programs\python\python37-32\Lib\runpy.py", line 193, in _run_module_as_main
"__main__", mod_spec)ERROR:tornado.application:Exception in callback None
Traceback (most recent call last):
File "D:\venv\lib\site-packages\tornado\ioloop.py", line 887, in start
fd_obj, handler_func = self._handlers[fd]
KeyError: 828

File "c:\users\ausaf\appdata\local\programs\python\python37-32\Lib\runpy.py", line 85, in _run_code
exec(code, run_globals)
File "D:\venv\openhtf\openhtf\output\servers\dashboard_server.py", line 189, in
main()
File "D:\venv\openhtf\openhtf\output\servers\dashboard_server.py", line 183, in main
DashboardPubSub.update_stations(list(stations))
File "D:\venv\openhtf\openhtf\output\servers\dashboard_server.py", line 38, in _discover
for host, response in multicast.send(query, **kwargs):
File "D:\venv\openhtf\openhtf\util\multicast.py", line 163, in send
sock.sendto(query.encode('utf-8'), (address, port))
OSError: [WinError 10051] A socket operation was attempted to an unreachable network
```