title: Deleting specific messages that was sent by the bot and sent by the user. Discord.py rewrite
body: <p>I'm having a lot of trouble with discord.py rewrite and its migration. I looked at the migrating to v1.0 site and it said to put in message.delete() and so I did but I realised that wasn't working so I put in ctx aswell. But that put it to an error. There are two commands with this error at the moment.</p>
  
  <p>I have already tried putting the message into a variable.</p>
  
  <pre><code>@client.command()
  async def clear(ctx, amount=100):
      message = ctx.message
      channel = ctx.message.channel
      messages = []
      await ctx.channel.purge(limit=int(amount+1))
      mymessage = await channel.send('Messages deleted')
      await ctx.message.delete(mymessage)
  
  @client.command()
  async def verify(ctx, *, arg):
      print(ctx.message.channel.id)
      print(ctx.message.author)
      if ctx.channel.id == 521645091098722305:
          role = await ctx.guild.create_role(name=arg)
          await ctx.message.author.add_roles(role)
          mymessage = await ctx.send('Done! Welcome!')
          await ctx.message.delete(mymessage)
          await ctx.message.delete(ctx.message)
  </code></pre>
  
  <p>I expected the output to delete the message. For the clear one it deletes it and then gives it back. for the verify one it just keeps it as the same and shows the error:
      raise CommandInvokeError(exc) from exc
  discord.ext.commands.errors.CommandInvokeError: Command raised an exception: TypeError: delete() takes 1 positional argument but 2 were given</p>
  
  <p>Also my role giving verify sometimes goes 3 times. I have went into task manager and killed all of the python too but it still did that. Once when I was clearing it said Done! Welcome as well. If you can answer this question as well, I would be pleased! Thank you in advance.</p>