Allow unique invites for Client.create_invite.

discord/client.py

@@ -896,8 +896,10 @@ class Client:
         temporary : bool
             Denotes that the invite grants temporary membership
             (i.e. they get kicked after they disconnect). Defaults to False.
-        xkcd : bool
-            Indicates if the invite URL is human readable. Defaults to False.
+        unique: bool
+            Indicates if a unique invite URL should be created. Defaults to True.
+            If this is set to False then it will return a previously created
+            invite.
 
         Raises
         -------

discord/http.py

@@ -544,7 +544,8 @@ class HTTPClient:
         payload = {
             'max_age': options.get('max_age', 0),
             'max_uses': options.get('max_uses', 0),
-            'temporary': options.get('temporary', False)
+            'temporary': options.get('temporary', False),
+            'unique': options.get('unique', True)
         }
 
         return self.request(r, json=payload)