* Add second crayon advisory
The crate already has an informational advisory, and this is clearly a separate issue despite affecting the same code.
* Adjust language to not imply intent w/ clippy
The warning silence was in a big pile of other changes and not necessarily done with intent to hide the issue.
As proposed in #240 and tracked in #414, this PR translates all
advisories into the new "V3" advisory format, which is based on Markdown
with leading TOML front matter.
This format makes it easier to see rendered Markdown syntax
descriptions, whether rendered by an IDE or GitHub. This should help
with both crafting advisories initially as well as review, and ideally
encourages more lengthy descriptions.
Support for this format shipped in `cargo-audit` v0.12.0 on
May 6th, 2020.
