Add vim-surround

.vimrc

@@ -3,6 +3,7 @@ call plug#begin('~/.vim/plugged')
 Plug 'tpope/vim-sensible'
 Plug 'tpope/vim-sleuth'
 Plug 'tpope/vim-fugitive'
+Plug 'tpope/vim-surround'
 Plug 'bling/vim-airline'
 Plug 'mhinz/vim-signify'
 Plug 'ctrlpvim/ctrlp.vim'