RFC: merging britney's Heidi output into sets/

["Adam D. Barratt" <adam@adam-barratt.org.uk>]

Hi,

For historical reasons, britney's "heidi set" output, and the SSH key
used to persist that output to the archive, live in britney/Heidi/set
and britney/ssh, respectively.

In all other cases where we pass a control-suite style file to dak, we
do so via a file in /srv/release.d.o/sets/${file}/ and a key
in /srv/release.d.o/sets/ssh/. (Britney also uses this location for
testing-debug files.)

I'd like to suggest that we remove the difference, by moving
britney/Heidi/set to sets/testing/, and the active SSH keys to sets/ssh.
If desired, we can symlink them back to the existing locations for
compatibility / finger memory.

This seems like it should just work[tm], but opinions or pointing out
what I've missed welcome.

Regards,

Adam