Working configuration file

gistfile1.yml

services:
    demo:
    tms:

layers:
  - name:            ginaBdl
    title:           GINA BDL
    sources:         [gina_bdl_cache]

caches:
    gina_bdl_cache:
        grids:       [global_mercator]
        sources:     [gina_bdl]

sources:
    gina_bdl:
        type:        tile
        url:         http://ecn.t3.tiles.virtualearth.net/tiles/a%(quadkey)s.jpeg?g=2868
        grid:        global_mercator

grids:
    global_mercator:
        base:        GLOBAL_WEBMERCATOR
        num_levels:  24