Add websocket for broadcasting InfluxDB to JS clients

[Jollyfant]

Shoul add a Python Websocket Server to broadcast data to HTML5 clients for the dashboard

[Jollyfant]

In JavaScript:

<script>
// Create WebSocket connection.
const socket = new WebSocket('ws://localhost:8765');

// Connection opened (sending does nothing)
socket.addEventListener('open', function (event) {
    socket.send('Ping');
});

// Listen for messages
socket.addEventListener('message', function (event) {
  console.log(event.data);
});
</script>

[Jollyfant]

See #4