Add compatibility shim for asyncio.Future creation.

Should provide better support for uvloop.

discord/compat.py

@@ -31,6 +31,15 @@ try:
 except AttributeError:
     create_task = asyncio.async
 
+try:
+    _create_future = asyncio.AbstractEventLoop.create_future
+except AttributeError:
+    def create_future(loop):
+        return asyncio.Future(loop=loop)
+else:
+    def create_future(loop):
+        return loop.create_future()
+
 try:
     run_coroutine_threadsafe = asyncio.run_coroutine_threadsafe
 except AttributeError: