[Imports] Import Nextbike stations

[Emil Linus Albrecht]

Nextbike is a huge bicycle rental service, operating in all of Europe. 
They have a public API which serves data on all stations, their names, 
coordinates, and capacity.

Some are already in OSM, but tagged wrongly or missing information.

I am currently unsure about the license, though getting permission 
shouldn't be a problem.



What do you all think?

-Emil