Inconsistent facet city
Looking at the current api it seems that there's a small inconsistency in the city facet across different endpoints:
- search/events requires the city to start uppercase, e.g. Berlin
- search/location requires locality to start uppercase, e.g. Berlin
- search/groups requires the city to start lowercase, e.g. berlin
Not a big issue but might still be nice to adjust this. Adding the pretty print alias city for search/location would be nice as well :)