handle_info instead of cast, @impl in serverkey

lib/chessh/ssh/daemon.ex

@@ -15,7 +15,8 @@ defmodule Chessh.SSH.Daemon do
   end
 
   def init(state) do
-    GenServer.cast(self(), :start)
+    send(self(), :start)
+
     {:ok, state}
   end
 
@@ -58,7 +59,7 @@ defmodule Chessh.SSH.Daemon do
   def pwd_authenticate(username, password, inet, _state),
     do: pwd_authenticate(username, password, inet)
 
-  def handle_cast(:start, state) do
+  def handle_info(:start, state) do
     port = Application.fetch_env!(:chessh, :port)
     key_dir = String.to_charlist(Application.fetch_env!(:chessh, :key_dir))
     max_sessions = Application.fetch_env!(:chessh, :max_sessions)

lib/chessh/ssh/server_key.ex

@@ -4,6 +4,7 @@ defmodule Chessh.SSH.ServerKey do
 
   @behaviour :ssh_server_key_api
 
+  @impl true
   def is_auth_key(key, username, _daemon_options) do
     PlayerSession.update_sessions_and_player_satisfies(
       username,
@@ -11,6 +12,7 @@ defmodule Chessh.SSH.ServerKey do
     )
   end
 
+  @impl true
   def host_key(algorithm, daemon_options) do
     :ssh_file.host_key(algorithm, daemon_options)
   end