Support More Detailed API

[conor-f]

A few things not in the API:

• Options for earliest/latest are accepted but don't look used
• Filter by Time of Day (e.g. between 09:00 and 12:00 for days in the above range). This isn't necessary but may be a nice to have. Can't be done on the front end as there's no time of journeys segment but I don't know if it's possible on the back end due to the way the caching of the geojson is done?
• Return road "speed" (Avg duration on segment / segment length I guess? Or median? Or a mix?)
• What format is the road quality in? Range from 0 - 100 where 0 is terrible and 100 is perfect?

I guess it'd look something like this for each point:

[
   {
       'segment_name': <String>,
       'quality': <int 0 - 100 (or float 0.0 - 1.0) where 0 is terrible quality>,
       'speed': <float of m/s of the speed of the road segment>,
       'usage': <int number of journeys that passed through this segment>
   },
   ...
]

Also, two other points. The footway stuff introduced in 0.0.16 seems to cause a crash and I can't find a working commit for the collisions stuff. It's complaining about constants COUNTY_MAP not being found or similar.

[RobertLucey]

Collisions / speed are included alongside quality / count on the general geojson now, at least from 0.0.44

The earliest / latest works but not for time of day, that isn't an option to be collected on the app even yet. If that's the only thing to do in this ticket might be good to have a separate issue for it
The quality from 0 to 100 is more like 5 to 50 or something, will formalize the scoring in a while, it's all a bit loose at the mo but can get a good idea with the weird range