title: discord.errors.Forbidden: 403 FORBIDDEN (error code: 50013): Missing Permissions
body: <p>I've recently created a bot which is only allowed to send messages and read message history. In my own servers, the bot seemed to work flawlessly, but a certain user tried using the bot on his own server and the error <code>discord.errors.Forbidden: 403 FORBIDDEN (error code: 50013): Missing Permissions</code> popped up.</p>
  
  <pre class="lang-py prettyprint-override"><code>await message.channel.send(file=discord.File(io.BytesIO(meme), filename="meme.png"))
  </code></pre>
  
  <p>The line above is what's causing the error. I'm thinking that I need the 'Attach Files' permission, but for some reason it works without it on my testing servers.</p>
  
  <p>Full traceback:</p>
  
  <pre><code>Traceback (most recent call last):
    File "/home/nemplayer/.local/lib/python3.7/site-packages/discord/client.py", line 270, in _run_event
      await coro(*args, **kwargs)
    File "bot/bot.py", line 78, in on_message
      await message.channel.send(file=discord.File(io.BytesIO(meme), filename="meme.png"))
    File "/home/nemplayer/.local/lib/python3.7/site-packages/discord/abc.py", line 806, in send
      content=content, tts=tts, embed=embed, nonce=nonce)
    File "/home/nemplayer/.local/lib/python3.7/site-packages/discord/http.py", line 218, in request
      raise Forbidden(r, data)
  discord.errors.Forbidden: 403 FORBIDDEN (error code: 50013): Missing Permissions
  </code></pre>