title: Discord.py create_custom_emojis usage
body: <p>I'm making a bot with Discord.py and I've some question how to use the function <code>create_custom_emojis()</code> because whatever I do, I keep getting the HTTP Error 400.</p>
  
  <p>Here's my code to create the emoji:</p>
  
  <pre><code>with open("data/emojis/image.png", "rb") as image:
      image_byte = image.read()
      emoji = await self.bot.create_custom_emoji(server, name="emo", image=image_byte)
  </code></pre>
  
  <p>And the error I get: </p>
  
  <pre><code>Traceback (most recent call last):
    File "C:\Program Files (x86)\Python35\lib\asyncio\tasks.py", line 239, in _step
      result = coro.send(None)
    File "C:\Users\armel\Downloads\Discord bot\Red-DiscordBot\cogs\moga.py", line 385, in read_feeds
      message = await self._feed_check(server, chan_id, name, infos)
    File "C:\Users\armel\Downloads\Discord bot\Red-DiscordBot\cogs\moga.py", line 198, in _feed_check
      await self.create_custom_emojis(server)
    File "C:\Users\armel\Downloads\Discord bot\Red-DiscordBot\cogs\moga.py", line 189, in create_custom_emojis
      emoji = await self.bot.create_custom_emoji(server, name=name, image=image_byte)
    File "lib\discord\client.py", line 2519, in create_custom_emoji
      data = yield from self.http.create_custom_emoji(server.id, name, img)
    File "lib\discord\http.py", line 202, in request
      raise HTTPException(r, data)
  discord.errors.HTTPException: BAD REQUEST (status code: 400)
  </code></pre>