Add __slots__ for missing classes that didn't have it.

discord/message.py

@@ -87,6 +87,11 @@ class Message:
         A list of attachments given to a message.
     """
 
+    __slots__ = [ 'edited_timestamp', 'timestamp', 'tts', 'content', 'channel',
+                  'mention_everyone', 'embeds', 'id', 'mentions', 'author',
+                  'channel_mentions', 'server', '_raw_mentions', 'attachments',
+                  '_clean_content', '_raw_channel_mentions' ]
+
     def __init__(self, **kwargs):
         # at the moment, the timestamps seem to be naive so they have no time zone and operate on UTC time.
         # we can use this to our advantage to use strptime instead of a complicated parsing routine.
@@ -124,7 +129,7 @@ class Message:
                 if channel is not None:
                     self.channel_mentions.append(channel)
 
-    @utils.cached_property
+    @utils.cached_slot_property('_raw_mentions')
     def raw_mentions(self):
         """A property that returns an array of user IDs matched with
         the syntax of <@user_id> in the message content.
@@ -134,7 +139,7 @@ class Message:
         """
         return re.findall(r'<@([0-9]+)>', self.content)
 
-    @utils.cached_property
+    @utils.cached_slot_property('_raw_channel_mentions')
     def raw_channel_mentions(self):
         """A property that returns an array of channel IDs matched with
         the syntax of <#channel_id> in the message content.
@@ -144,7 +149,7 @@ class Message:
         """
         return re.findall(r'<#([0-9]+)>', self.content)
 
-    @utils.cached_property
+    @utils.cached_slot_property('_clean_content')
     def clean_content(self):
         """A property that returns the content in a "cleaned up"
         manner. This basically means that mentions are transformed