Rebranding: replace Vector by Riot everywhere in the git and github repos

- Rename categories

Riot/Model/Room/RoomDataSource.m

@@ -1,5 +1,6 @@
 /*
  Copyright 2015 OpenMarket Ltd
+ Copyright 2017 Vector Creations Ltd
  
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -19,7 +20,7 @@
 #import "EventFormatter.h"
 #import "RoomBubbleCellData.h"
 
-#import "MXKRoomBubbleTableViewCell+Vector.h"
+#import "MXKRoomBubbleTableViewCell+Riot.h"
 #import "AvatarGenerator.h"
 
 #import "MXRoom+Vector.h"