Sign column and cursor line number should be transparent when one_nvim_transparent_bg is true

[cubetastic33]

Right now when one_nvim_transparent_bg is true, the sign column and cursor line number look like this:

But they should have transparent backgrounds too.

This can be fixed with highlight SignColumn guibg=0 and highlight CursorLineNr guibg=0 but I think it should be part of the colorscheme.