Overlay coastline on tile

[ahuang11]

What if you just do

import geoviews as gv
import cartopy.crs as ccrs
gv.extension("bokeh")

gv.Points(([-88], [40])).opts(projection=ccrs.GOOGLE_MERCATOR, global_extent=True) * gv.feature.coastline() * gv.tile_sources.OSM()