~/.vimrc: Make gitgutter prettier.

.vimrc

@@ -18,6 +18,7 @@ if isdirectory($HOME . '/.vim/bundle/vundle')
	Bundle 'tpope/vim-foreplay'
	Bundle 'airblade/vim-gitgutter'
	highlight SignColumn ctermbg=0
	Bundle 'terryma/vim-multiple-cursors'
endif