Added prune all user command

src/main/cogs/management.py

@@ -0,0 +1,29 @@
+import asyncio
+import discord
+import traceback
+import discord
+from discord.ext import commands
+from misc import checks
+from misc import exceptions as exc
+
+class Administration:
+
+    def __init__(self, bot):
+        self.bot = bot
+
+    @commands.command(name='prunealluser')
+    @commands.is_owner()
+    async def prune_all_user(self, ctx, uid):
+    channels = ctx.message.guild.channels
+    member = ctx.message.guild.get_member(uid)
+    history = {}
+    c = 0
+    for channel in channels:
+        history[channel.id] = await channel.history().flatten()
+        print('Added: ' + channel.id)
+    for channel, messages in history.items():
+        for message in messages:
+            if message.author is member:
+                await message.delete()
+                c += 1
+    await ctx.send('✅ `' + c + '` **messages deleted from the server.**')