Adds method to get Portugal speed limits by vehicle

- Adds OSM Vehicle Types and Road Types (constants)
- Creates dictionary with lists of speed limits 
sorted by road type (also from OSM) and grouped by
vehicle type
- Adds function to retrieve a type of vehicle speed
limits (list) given the vehicle type
Switches & refactors response tuple (route/track)
Complex data structure for Portugal speed limits

- Dictionary of dictionaries
- Each key is an OSM vehicle type
- Each value is a dict mapping road types w/speed
limits

e.g.

{
 CAR: { MOTORWAY: 120, TRUNK: 100, PRIMARY: ... },
 GOODS: { MOTORWAY: 110, TRUNK: 90, PRIMARY: ... },
 ...
}
Adds speed limits to Routino router.cgi URL

- Given the vehicle type, a method creates the URL
parameter with all speed limits for that vehicle
- Routino router.cgi URL is built using the new 
URL parameter (with speed limits)
- Flask API also accepts the vehicle type as a URL
parameter and uses it to retrieve the speed limits
Refactoring to rename variable and keep with PEP-8