travis: add latest Ruby version

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

travis: remove Ruby 1.8

Too old. We'll make it work later.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

Fix EDITOR support with arguments

Reported-by: Max Horn <max@quendi.de>
Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

Add README

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>