v0.8.0

• Updates
  • Update Livebook to v0.8.0
  • Reduced logger level to warning to reduce clutter when evaluating cells.
    This is a the same default level as regular Livebook.
  • Support the shutdown button. This will gracefully power off your device.
    Note that Nerves Livebook syncs notebooks to minimizing losing notebook
    changes already, but this is an additional way to make sure everything has been
    flushed to storage when you're done.
  • Update Nerves systems to nerves_system_br 1.21.6 versions (Erlang/OTP 25.2)
  • Update all provided mix libraries to their latest.