cleanup attachments
cleanup attachments

dr-em/BotBuilder,yakumo/BotBuilder,stevengum97/BotBuilder,xiangyan99/BotBuilder,dr-em/BotBuilder,stevengum97/BotBuilder,yakumo/BotBuilder,yakumo/BotBuilder,msft-shahins/BotBuilder,Clairety/ConnectMe,stevengum97/BotBuilder,xiangyan99/BotBuilder,mmatkow/BotBuilder,mmatkow/BotBuilder,Clairety/ConnectMe,mmatkow/BotBuilder,dr-em/BotBuilder,msft-shahins/BotBuilder,xiangyan99/BotBuilder,yakumo/BotBuilder,xiangyan99/BotBuilder,mmatkow/BotBuilder,msft-shahins/BotBuilder,stevengum97/BotBuilder,msft-shahins/BotBuilder,Clairety/ConnectMe,Clairety/ConnectMe,dr-em/BotBuilder