fix(MessageDeleteBulkAction): remove bulkDeleted messages from cache

Fixes #2382

src/client/rest/RESTMethods.js

@@ -172,12 +172,13 @@ class RESTMethods {
   }
 
   bulkDeleteMessages(channel, messages) {
+    const ids = messages.map(m => m.id);
     return this.rest.makeRequest('post', Endpoints.Channel(channel).messages.bulkDelete, true, {
-      messages: messages.map(m => m.id),
+      messages: ids,
     }).then(() =>
       this.client.actions.MessageDeleteBulk.handle({
         channel_id: channel.id,
-        messages,
+        ids,
       }).messages
     );
   }