v0.57.0

Fixes

• fdf2925: fixed #625 - rand crate breakage (#628) (Eugene) #628
  • Note that this bumps the internal rand-core dependency. The stable rand-core dependency is still re-exported as russh::keys::ssh_key::rand_core.
• e265845: Make Config accessor methods for user/port/host public (#620) (Adam Chappell) #620