Drop the Package-Requires field for now

I have absolutely no idea what this thing requires, so drop the field
for now.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>
Add tests

Yes, I'm bad, won't happen again, ERT is kinda neat.

Signed-off-by: Gergely Nagy <algernon@madhouse-project.org>