title: How can i get all roles with a certain permission
body: <p>I was creating a ticket system and I wanted it to work in multiple servers but I can't figure out how to get all roles in a server with a certain permission. Or maybe an extra command for people to add roles who can see the channels. But I don't know how?
  This is what i have atm:</p>
  
  <pre class="lang-py prettyprint-override"><code>@bot.command(name='ticket', aliases=['Ticket'])
  async def ticket(ctx):
      ticketnum = random.randint(1000,9999)
      guild = ctx.message.guild
      channel = await guild.create_text_channel(name=f'Ticket-{ticketnum}')
      channel.set_permissions(guild.default_role, read_messages=False)
      await ctx.send(f'Created ticket: {channel}')
  </code></pre>