assert failure generating the map

[chadwhitacre]

Reticketing from #76.

Traceback (most recent call last):
  File "./genmap.py", line 544, in <module>
    main(topics, fp, **args.__dict__)
  File "./genmap.py", line 523, in main
    output_svg(topics, fp, big, blocks)
  File "./genmap.py", line 450, in output_svg
    block.assign_ids(pathways)
  File "./genmap.py", line 371, in assign_ids
    , relax_crossings_until=1e8
  File "/Users/whit537/workbench/saxifrage/caac-map/pathways_solver.py", line 129, in solve
    problem = Problem(shapes, pathways, take_first, relax_assignments_until, relax_crossings_until)
  File "/Users/whit537/workbench/saxifrage/caac-map/pathways_solver.py", line 80, in __init__
    assert len(self.resources) == nlevels, (self.resources, nlevels, shapes, pathways)
AssertionError: (('phipps-conservatory-phipps-cafe', 'carnegie-library-of-pittsburgh-cooking-for-teens-', 'food-n-me-vari