[channel] implement channel categories

disco/api/client.py

@@ -291,11 +291,14 @@ class APIClient(LoggingClass):
             bitrate=None,
             user_limit=None,
             permission_overwrites=[],
+            parent_id=None,
             reason=None):
+
         payload = {
             'name': name,
             'channel_type': channel_type,
             'permission_overwrites': [i.to_dict() for i in permission_overwrites],
+            'parent_id': parent_id,
         }
 
         if channel_type == 'text':

disco/types/channel.py

@@ -19,6 +19,7 @@ ChannelType = Enum(
     DM=1,
     GUILD_VOICE=2,
     GROUP_DM=3,
+    GUILD_CATEGORY=4,
 )
 
 PermissionOverwriteType = Enum(
@@ -175,7 +176,7 @@ class Channel(SlottedModel, Permissible):
         """
         Whether this channel belongs to a guild.
         """
-        return self.type in (ChannelType.GUILD_TEXT, ChannelType.GUILD_VOICE)
+        return self.type in (ChannelType.GUILD_TEXT, ChannelType.GUILD_VOICE, ChannelType.GUILD_CATEGORY)
 
     @property
     def is_dm(self):
@@ -214,6 +215,13 @@ class Channel(SlottedModel, Permissible):
         """
         return self.client.state.guilds.get(self.guild_id)
 
+    @cached_property
+    def parent(self):
+        """
+        Parent this channel belongs to (or None if not applicable).
+        """
+        return self.guild.channels.get(self.parent_id)
+
     def messages_iter(self, **kwargs):
         """
         Creates a new `MessageIterator` for the channel with the given keyword
@@ -422,6 +430,16 @@ class Channel(SlottedModel, Permissible):
         assert (self.is_voice)
         return self.client.api.channels_modify(self.id, user_limit=user_limit, reason=reason)
 
+    def set_parent(self, parent, reason=None):
+        """
+        Sets the channels parent.
+        """
+        assert (self.is_guild)
+        return self.client.api.channels_modify(
+            self.id,
+            parent_id=to_snowflake(parent) if parent else parent,
+            reason=reason)
+
 
 class MessageIterator(object):
     """