Make airline use insert colors for terminal mode

.vimrc

@@ -95,6 +95,8 @@ nnoremap <C-]> :tabnext<cr>
 
 " ------ nvim specific ------
 if has('nvim')
+  let g:airline#themes#dark#palette.terminal = copy(g:airline#themes#dark#palette.insert)
+
   tnoremap jj <C-\><C-N>
   tmap <C-[> <C-\><C-N><C-[>
   tmap <C-]> <C-\><C-N><C-]>