~/.emacs.d: update melpa link

.emacs.d/init.el

(require 'package)
(add-to-list 'package-archives '("marmalade" . "http://marmalade-repo.org/packages/"))
(add-to-list 'package-archives '("melpa" . "http://melpa.milkbox.net/packages/"))
(add-to-list 'package-archives '("melpa" . "http://melpa.org/packages/"))
(add-to-list 'auto-mode-alist '("\\.edn\\'" . clojure-mode))