Switching to a non-native package

[Zygmunt Krynicki]

I'd like to work on enabling Debian in the CI loop and I was thinking
that it would be somewhat easier we switched to non-native packaging
in the upstream tree and similarly switched to quilt in the Debian
tree (we could have separate packaging trees for sid / stretch if that
would help). Since my view may be simplistic I would like to ask the
current most active Debian maintainers of snapd for opinion.

Right now almost all of the CI in the tree is performed on the
packaging that is in the tree as well. The notable exception is 14.04
which has a separate packaging branch. This is unrealistic as the
Debian packaging tree is widely different and even if we built a
package from the in-tree debian directory and tested it on a real
Debian machine the result would not be representative of what a
subsequent upstream release would look like in Debian.

I'd like to propose that we remove the debian directory from the
upstream repository (no special casing) and work on ensuring that
Ubuntu and subsequently Debian are tested equally well whenever we
make a pull request.

Best regards
ZK