Preload 10m-populated-places-simple

[mguentner]

Currently the project.mml file produced by make.py contains the hardcoded url
to the 10m-populated-simple shapefile:

"Datasource": {
        "dbname": "gis", 
        "extent": "-20037508.34,-20037508.34,20037508.34,20037508.34", 
        "file": "http://mapbox-geodata.s3.amazonaws.com/natural-earth-1.4.0/cultural/10m-populated-places-simple.zip", 
        "host": "172.17.0.3", 
        "port": "5432", 
        "user": "osm"
      }, 
      "class": "", 
      "geometry": "point", 
      "id": "ne_places", 
      "name": "ne_places", 
      "srs": "", 
      "srs-name": "autodetect"
    }, 

which should be downloaded and extracted during the build of the Dockerfile.

The problem is that make.py does not allow to set ne_places in configure.py.
Therefore we can't preload the zip or use the shapefile produced by get_shapefiles.sh (openstreetmap-carto style).

Reference:
https://github.com/mapbox/osm-bright/blob/ca6c3795db9334cf21577aa934e11c531aff9d52/make.py#L43
" # Assume all other layers are PostGIS layers"