Support free floating bikes on GBFS

[eskerda]

See, for instance, coast bike share https://gbfs.hopr.city/api/gbfs/8/ (#236)

[Altonss]

Well if you look in the details, this feed also contains classical docked bikes (on stations) :)

[Ephtolens]

If i can dig up this issue, i would suggest those type of GBFS : https://gbfs.getapony.com/v1/Tours/en/gbfs.json
This is a more or less valid GBFS (according to the validator)
Actually, there is no capacity mentioned in station_information, and no station_id mentioned for each bike. (in free_bike_status)
Without those informations it's a bit complicated to add it to this repo, maybe i'll try to reach pony to ask if they could comply to GBFS standard.
Is that this type of free floating bike you were mentioning to support in pybikes ?