v2.13.0

• Reject slicer toxics with average_size <= 0 or size_variation outside [0, average_size],
  and stop the slicer from recursing forever on degenerate sizes (#774, @iyaz-shaikh)
• Add optional bearer token auth for the HTTP API via TOXIPROXY_AUTH_TOKEN, supported by the Go
  client and toxiproxy-cli, and warn when the API is unauthenticated on a non-loopback address
  (#774, @iyaz-shaikh)
• Fix removing a toxic hanging forever, and freezing the whole HTTP API, when the downstream
  toxic or connection is already gone (#760, @matheusgb)
• Fix the bandwidth toxic hanging or panicking when rate <= 0 (#764, @jaideeppyne)
• Update go version to 1.27 (#777, @The-Black-Fox)
• Update various go packages