Fails to convert svg (which contains <use> tags)

まだ誰も着手していません。

The attached svg does not seem to get converted in to the png sprite (nor does it throw an error btw).

I suspect the tags to cause the problem
a- is there a way to ensure it *does* convert? and if not
b- do you have any recommendation on any tools that can replace tags with the referenced tags? preferably a commandline tool rather than some gui

[Star.svg.zip](https://github.com/mapbox/spritezero-cli/files/1734799/Star.svg.zip)

Use the attached Star.svg as the reproduction and run it through the CLI to confirm the silent conversion failure. The issue names no source files or tests, so trace the SVG conversion entry point and add or update coverage for elements; done means the SVG converts successfully or the limitation is documented with a clear recommendation.

索引モデルが issue の本文から書いたものです。