Game Logs

Whenever "war" events happen, we want to log them. For now, let's just add the functionality to publish them, and we'll let the messages pile up in the logs queue.

1. Add a PublishGob function to the internal/pubsub package.
   1. It should be similar to the PublishJSON function, but encode to gob
   2. Set the ContentType option to application/gob
2. Update the war handler function in the client to publish game logs.
   1. Capture the winner and loser return values from the GameState's HandleWar method and use them to create the log message.
      1. If the outcome is that the opponent won, the message should say "{winner} won a war against {loser}".
      2. If the outcome is that the player won, the message should also say "{winner} won a war against {loser}".
      3. If the outcome is a draw, the message should say "A war between {winner} and {loser} resulted in a draw".
   2. Create a reusable function to publish a GameLog struct:
      1. The topic exchange.
      2. The GameLogSlug.username routing key, where username is the name of the player who initiated the war, and GameLogSlug is a constant in the routing package.
      3. The GameLog struct should be serialized using the PublishGob function. Fill all the fields in.
   3. If a publishing fails, NackRequeue, otherwise Ack.
3. Test the code.
   1. Spin up two clients and a server. Make sure the game_logs queue exists.
   2. Have one client spawn a unit: spawn americas infantry
   3. Have the other client spawn a unit: spawn europe cavalry
   4. Have the first client declare war by moving a unit into the other client's territory: move europe 1
   5. Repeat with different matchups to trigger each war outcome (you win, opponent wins, draw). You need at least three logs in the game_logs queue before submitting.

You should be able to verify in the RabbitMQ management UI that a log was published to the game_logs queue.

Run and submit the CLI tests.