git: use bufio.Scanner instead of bufio.Reader

Welcome Go 1.1 :-)
git: remove dead code
provision/juju: use bufio.Scanner instead of bufio.Reader
readme: remove travis-ci ribbon

I'm not disabling Travis, yet, but since it does not support Go 1.1 yet
(see travis-ci/travis-ci#1110), I'm not displaying the ribbon anymore.
We may drop it entirely, or re-add the ribbon later.