Topojson bbox should not be transformed when loading Topojson-dict

[mattijn]

According the Topojson specification:

To include information on the coordinate range for a topology or geometry a TopoJSON object may have a member named “bbox”. The value of the bbox member must be a 2*n array where n is the number of dimensions represented in the contained geometries, with the lowest values for all axes followed by the highest values. The axes order of a bbox follows the axes order of geometries. The bounding box should not be transformed using the topology’s transform, if any.

Example where it is going wrong:

import topojson
data = {
    "foo": {"type": "LineString", "coordinates": [[0, 0], [1, 0], [2, 0]]},
    "bar": {"type": "LineString", "coordinates": [[0, 0], [1, 0], [2, 0]]},
}
tj = topojson.Topology(data).to_dict()
tj

{'type': 'Topology',
 'objects': {'data': {'geometries': [{'type': 'LineString', 'arcs': [0]},
    {'type': 'LineString', 'arcs': [0]}],
   'type': 'GeometryCollection'}},
 'bbox': (0.0, 0.0, 2.0, 0.0),
 'transform': {'scale': [2.000002000002e-06, 1], 'translate': [0.0, 0.0]},
 'arcs': [[[0, 0], [500000, 0], [499999, 0]]]}

Here is the 'bbox': (0.0, 0.0, 2.0, 0.0), but upon loading as Topojson-dict it changes to 'bbox': (0, 0, 500000, 0):

tp.Topology(tj, object_name='data').to_dict()

{'type': 'Topology',
 'bbox': (0, 0, 500000, 0),
 'objects': {'data': {'geometries': [{'type': 'LineString', 'arcs': [0]},
    {'type': 'LineString', 'arcs': [0]}],
   'type': 'GeometryCollection'}},
 'transform': {'scale': [2.000002000002e-06, 1], 'translate': [0.0, 0.0]},
 'arcs': [[[0, 0], [500000, 0], [499999, 0]]]}

[mattijn]

Fix by #139