Fix failing kubepkg debs test
Fix failing kubepkg debs test

This fixes the failing `kubepkg debs` test which was failing because of
the shelling-out `mv` command which resulted in a permission denied
error. We fixed that by using the golang ioutils to copy the file
around.

Signed-off-by: Sascha Grunert <70ab469ddb2ac3e35f32ed7c2fd1cca514b2e879@suse.com>

kubernetes/release,kubernetes/release