Load plugin from master.

    $ antigen-bundle $PLUGIN_DIR

    Cloning into '.+?'\.\.\. (re)
    done.
    $ hehe
    hehe
  
  Update the plugin.

    $ cat > $PLUGIN_DIR/aliases.zsh <<EOF

    > alias hehe='echo hehe, updated'
    > EOF
    $ pg commit -am 'Updated message'
    \[master [a-f0-9]{7}\] Updated message (re)
     1 file changed, 1 insertion(+), 1 deletion(-)
  
  Update bundles.
  
    $ antigen-update

    From \S+? (re)

       [a-z0-9]{7}\.\.[a-z0-9]{7}  master     -> origin/master (re)
    Updating [a-z0-9]{7}\.\.[a-z0-9]{7} (re)
    Fast-forward
     aliases.zsh |    2 +-
     1 file changed, 1 insertion(+), 1 deletion(-)
  
  Confirm there is still only one repository.
  
    $ ls $ADOTDIR/repos | wc -l
    1
  
  The new alias should not activate.
  
    $ hehe
    hehe