The new flag `--skip-sign` as the same effect as saying
`artifacts: none`. It lets non GPG key owners (like Travis)
use it.
Signed-off-by: Yoan Blanc <yoan.blanc@exoscale.ch>
The unit tests needs a test key to work with. I have tried to create a
test keyring on the fly and while that worked I was not able to
successfully sign with that. gpg would bail with an ioctl error which I
didn't track down since using a static key works.
