Add !failure command

[EchoFrost]

Should include a message that mentions the command user and adds the following text:
' is a market failure'

💹

    elif message.content.startswith('!failure'):
        msg = '{0.author.mention} is a market failure'.format(message)
        yield from channel.send(msg)

[AtomicW0mbat]

I looked through the description for Slash commands on the Discord developer page and I couldn't find a way to make it a mention a poster. Any thoughts on this? @EchoFrost

[EchoFrost]

I would consider exploring the optional 'allowed_mentions' field. This takes an object that should give you control over user mentions.
https://discord.com/developers/docs/interactions/slash-commands#interaction-response-interactionapplicationcommandcallbackdata
https://discord.com/developers/docs/resources/channel#allowed-mentions-object