Add fuzzing seeds for gif_read target

[Shnatsel]

Add fuzzing seeds for gif_read target generated by seeding afl and cargo-fuzz with AFL's libgif and imagemagick autogenerated corpus, fuzzing gif crate, and subsequently minifying them with cargo fuzz cmin.

Not sure if I should open a PR against this repo or https://github.com/rust-fuzz/seeds

[frewsxcv]

Not sure if I should open a PR against this repo or https://github.com/rust-fuzz/seeds

Either place is fine. Unsure if it makes sense to have the seeds in a separate repo. If you have opinions about it, I'd be interested to hear them.

[frewsxcv]

@bors r+

[frewsxcv]

bors r+

[bors[bot]]

Build succeeded

• continuous-integration/travis-ci/push