Rollbot instance now provides manual post to given group

src/rollbot.py

@@ -129,3 +129,6 @@ class Rollbot:
 
         t = time.time() - t
         self.logger.info(f"Exiting command thread for {message.message_id} after {t:.3f}s")
+
+    def manually_post_message(self, message_text, group_id):
+        self.callback(message_text, self.bot_lookup[group_id])