add undodir

Makefile

@@ -82,6 +82,7 @@ sublime:
 
 vim:
 	@printf "$(YELLOW)--- vim ------------------------------------------------\n$(RESET)"
+	mkdir -p ~/.vim/undodir
 	git submodule update --init -- vim/.vim/bundle
 	stow -t "$$HOME" vim
 

vim/.vimrc

@@ -9,6 +9,8 @@ set smarttab
 set tabstop=4
 set shiftwidth=4
 set expandtab
+set undofile
+set undodir=~/.vim/undodir
 
 set nrformats-=octal