add widget for choosing a date/time/interval in the side dashboard

[EddyIonescu]

No description provided.

[ckrajewski]

@EddyIonescu does this still need to be worked on?
I see a date and time picker, but I don't see an "interval" option
Also, I don't believe it's wired to anything
Is the point to show historical data?
As in where the buses/routes were at that given time?

[EddyIonescu]

So with an interval option, we'd be able to show aggregate metrics, like avg travel time of all buses between times A and B. The API supports in the schema, but currently returns Null for all those fields (that's what I'm currently working on, should have time this weekend to work on that). So yes, this ticket is useful :)

[EddyIonescu]

This one is just as useful (would look cooler when done), and should be more interesting - #44