As someone who has personal projects that take untrusted zips as input,
it is important to me to be able to fuzz the zip project to simulate
possible inputs and to ensure the projects are not vulnerable.
This commit adds a cargo fuzz module for reading and extracting input.
The `fuzz` directory was scaffolded with a `cargo fuzz init`
I added a CI step to guard against the fuzz module decaying over time.
