updated the copy-mode keybindings

tmux/tmux#754

tmux.conf

@@ -16,12 +16,12 @@ set -g mouse on
 setw -g mode-keys vi
 
 # Setup 'v' to begin selection as in Vim
-bind-key -t vi-copy v begin-selection
-bind-key -t vi-copy y copy-pipe "reattach-to-user-namespace pbcopy"
+bind-key -T copy-mode-vi v begin-selection
+bind-key -T copy-mode-vi y copy-pipe "reattach-to-user-namespace pbcopy"
 
 # Update default binding of `Enter` to also use copy-pipe
-unbind -t vi-copy Enter
-bind-key -t vi-copy Enter copy-pipe "reattach-to-user-namespace pbcopy"
+unbind -T copy-mode-vi Enter
+bind-key -T copy-mode-vi Enter copy-pipe "reattach-to-user-namespace pbcopy"
 
 # Open new/split windows in the current pane's path
 bind c new-window -c "#{pane_current_path}"