Release a new version of `chacha20poly1305` now that `zeroize` is not blocked to `<1.5`

[poliorcetics]

Without this, it is not possible to use this crate in the same dependency tree as https://github.com/RustCrypto/RSA since it has num-bigint-dig v0.8.1 which needs zeroize >= 1.5

[poliorcetics]

This also needs to update the dependency on chacha20 to version 0.9.0 at least

[tarcieri]

See the master tracking issue here: RustCrypto/utils#723

[poliorcetics]

I think everything has been updated, a new version should be published to make it available to people using crates.io

[tarcieri]

I can cut a prerelease if that's helpful. However, the next final release with a minor version bump would ideally include a new release of poly1305 based on universal-hash v0.5

[tarcieri]

I cut a v0.10.0-pre release: #406

We'll hopefully have a final release out soon