feat(dotfiles): teach `gg` to run `gg test` if first arg starts with `test/`
feat(dotfiles): teach `gg` to run `gg test` if first arg starts with `test/`

Just a convenience to save some typing, and because on a few occasions I
have typed this unthinkingly anyway, expecting it to work.

wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent,wincent/wincent