Set event loop to Selector on windows
With the [3.8 python update](https://docs.python.org/3/whatsnew/3.8.html#asyncio), the default event loop on windows is now the `ProactorEventLoop`; one of aiohttp's dependencies uses features which are not supported in this event loop leading to crashes on startup on windows with an undescriptive error

```
From cffi callback <function _sock_state_cb at 0x0000000003816040>:
Traceback (most recent call last):
  File "C:\\Users\\Numerlor\\.virtualenvs\\bot-K_QdelnW\\lib\\site-packages\\pycares\\__init__.py", line 91, in _sock_state_cb
    sock_state_cb(socket_fd, readable, writable)
  File "C:\\Users\\Numerlor\\.virtualenvs\\bot-K_QdelnW\\lib\\site-packages\\aiodns\\__init__.py", line 105, in _sock_state_cb
    self.loop.add_reader(fd, self._handle_event, fd, READ)
  File "C:\\Users\\Numerlor\\AppData\\Local\\Programs\\Python\\Python38\\Lib\\asyncio\\events.py", line 501, in add_reader
    raise NotImplementedError
NotImplementedError
```
This can be fixed by setting the event loop policy to `WindowsSelectorEventLoopPolicy` through `asyncio.set_event_loop_policy` when the platform is detected to be windows
diff --git a/bot/__init__.py b/bot/__init__.py
index 2dd4af22..4131b69e 100644
--- a/bot/__init__.py
+++ b/bot/__init__.py
@@ -1,3 +1,4 @@
+import asyncio
 import logging
 import os
 import sys
@@ -59,3 +60,8 @@ coloredlogs.install(logger=root_log, stream=sys.stdout)
 logging.getLogger("discord").setLevel(logging.WARNING)
 logging.getLogger("websockets").setLevel(logging.WARNING)
 logging.getLogger(__name__)
+
+
+# On Windows, the selector event loop is required for aiodns.
+if os.name == "nt":
+    asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
diff --git a/bot/bot.py b/bot/bot.py
index 49fac27e..a85a22aa 100644
--- a/bot/bot.py
+++ b/bot/bot.py
@@ -76,7 +76,7 @@ class Bot(commands.Bot):
             await self._resolver.close()
 
         if self.stats._transport:
-            await self.stats._transport.close()
+            self.stats._transport.close()
 
     async def login(self, *args, **kwargs) -> None:
         """Re-create the connector and set up sessions before logging into Discord."""
['bot/bot.py', 'bot/__init__.py']