- Major version for boring-sys: `PasswordCallback` was removed
- Major version for boring: the public `*Ref` types were removed and `foreign-types` appears in our public api and had a major version bump
- Patch version for tokio-boring: the only API change was removing the `S: Debug` bound
- Patch version for hyper-boring: no API changes, only removed dependencies
`tokio_boring::HandshakeError` currently requires that the inner stream
implements `Debug` for its `Display` implementation. This constraint is
unnecessary.
This change removes this `Debug` constraint so `HandshakeError` always
implements `Display`.