Neovim ignores `&t_Co` and `&term`, so it is not possible in Neovim to
use the ANSI colors when `termguicolors` is not set.
Re-add this option to override the value of `s:t_Co`.
Fixes https://github.com/lifepillar/vim-solarized8/issues/71.
Merge dark and light variants together. Now, you must select the
background color before loading the colorscheme, e.g.:
se background=dark
colorscheme solarized8
