Remove tmux vi copy/paste

The binding command has changed across versions of tmux. Rather than
write a conditional, we remove this customisation and stick with the
normal commands. It is used infrequently enough that this has proven
okay.

tmux/tmux.conf

@@ -33,10 +33,6 @@ set-window-option -g mode-keys vi # vi keys in copy mode (prefix+[)
 # General Key Bindings
 #######################
 
-# Act like vim. Enhance copy mode to use more vim like keys for copying.
-bind-key -t vi-copy 'v' begin-selection
-bind-key -t vi-copy 'y' copy-selection
-
 # Use prefix+r to reload the config file.
 bind-key C-r source-file ~/.tmux.conf \; display-message "tmux.conf reloaded"