Remove assumption in test about presence of a git config

The tests listed below run git commit which fails when a git config does not provide user.email.

+ test/test-ghe-backup-repositories-rsync.sh
+ test/test-ghe-restore.sh
+ test/test-ghe-backup.sh
Rename libexec to share/github-backup-utils

sed -i '' -e 's/libexec/share\/github-backup-utils/g' $(git ls-files)
mkdir -p share/github-backup-utils
git mv libexec/* share/github-backup-utils
sed -i '' -e 's|)/\.\.|)/\.\./\.\.|g' $(git ls-files share)
Add debian packaging
Merge remote-tracking branch 'spotify/master'

Conflicts:
	share/github-backup-utils/ghe-backup-es-v0.9-rsync
	share/github-backup-utils/ghe-backup-es-v1.x-rsync