Implement POST client method

lib/nntp/tiny/client.py

@@ -160,6 +160,20 @@ class Client(Connection):
 
         return message
 
+    def message_post(self, message: Message):
+        response = self.request('POST')
+
+        if response.code is not ResponseCode.NNTP_INQUIRY_ARTICLE:
+            raise ClientException(response)
+
+        self.message_send(message, MessagePart.WHOLE)
+        self.end()
+
+        response = self.response_read()
+
+        if response.code is not ResponseCode.NNTP_ARTICLE_RECEIVED:
+            raise RemoteException(response)
+
     def message_offer(self, message: Message):
         response = self.request('IHAVE', message.message_id)