Support warping in the Places API

[darribas]

We currently do not support warping the tiles pulled within the Place API. It'd be good to add a crs parameter specifying the CRS for the data retrieved and "plottable".

This should be an easy fix to pass here:

https://github.com/geopandas/contextily/blob/cbd968eabefac598f5b975e957f0b1cb453b259f/contextily/place.py#L131:L138

I think we just need to make it an explicit parameter here:

contextily/contextily/place.py

Line 72 in cbd968e

self, search, zoom=None, path=None, zoom_adjust=None, source=None, url=None

and document it.