Allow auto-fetch of train information

[danieldafoe]

App should allow you to choose how often you want to fetch for new data. This should obviously be done via AJAX.

Will likely implement with React.

[danieldafoe]

Auto-fetch is a possibility, but perhaps only by selecting a checkbox for how frequently you want the page to update itself.

[graypegg]

Could be done with web sockets! The server already does the data scraping, so formatting it to send only what's changed to all clients via a websocket shouldn't be too hard to implement.

[danieldafoe]

Good idea, @toish . I'm reluctant to implement this feature because I don't want to hit the GO Transit website with too many requests.