There were unauthenticated packages and -y was used without
--allow-unauthenticated. Using "--allow-unauthenticated" with
apt-get disables package verification
This commit introduces a self contained Neovim build which runs
SpaceVim. This has multiple uses:
* Easy debugging environment. Quickly check if the problem is your
machine or really a bug in SpaceVim.
* Portability across machines as long as the destination has Docker
support.
