check admin status properly in DM

bot.py

@@ -1,7 +1,9 @@
 import inspect
+import itertools
 import logging
 import os
 
+import discord
 from discord.ext import commands
 
 import lib
@@ -9,6 +11,7 @@ import heavynode
 
 
 DISCORD_TOKEN = os.environ['discord_token']
+DISCORD_SERVER_ID = 530446700058509323
 HEAVYNODE_TOKEN = os.environ['heavynode_token']
 
 
@@ -19,8 +22,19 @@ hn = heavynode.Client(HEAVYNODE_TOKEN)
 bot.add_cleanup(hn.shutdown)
 
 
+async def is_admin(ctx):
+    user = ctx.message.author
+    guild = discord.utils.get(bot.guilds, id=DISCORD_SERVER_ID)
+    member = discord.utils.get(guild.members, id=user.id)
+    if member is not None:
+        for role in member.roles:
+            if role.name == 'Admin' or role.name == 'Mod':
+                return True
+    return False
+
+
 @bot.command()
-@commands.has_any_role('Admin', 'Mod')
+@commands.check(is_admin)
 async def add(ctx, player):
     """Add a player to the server whitelist. Must use exact Minecraft name."""
     await hn.send_command(f'whitelist add {player}')
@@ -28,7 +42,7 @@ async def add(ctx, player):
 
 
 @bot.command()
-@commands.has_any_role('Admin', 'Mod')
+@commands.check(is_admin)
 async def remove(ctx, player):
     """Remove a player from the server whitelist. Must use exact Minecraft name."""
     await hn.send_command(f'whitelist remove {player}')