Make AuditLogDiff.roles an empty list instead of None.

discord/audit_logs.py

@@ -157,7 +157,7 @@ class AuditLogChanges:
             self.before.color = self.before.colour
 
     def _handle_role(self, first, second, entry, elem):
-        setattr(first, 'roles', None)
+        setattr(first, 'roles', [])
 
         data = []
         roles = entry.guild.roles

docs/api.rst

@@ -1380,7 +1380,7 @@ this goal, it must make use of a couple of data classes that aid in this goal.
         *List[Union[:class:`Role`, :class:`Object`]]* – A list of roles being added or removed
         from a member.
 
-        If a role is not found then it is a :class:`Object` with the ID being
+        If a role is not found then it is a :class:`Object` with the ID and name being
         filled in.
 
     .. attribute:: nick