Remove yasnippets from the list of default packages

Prelude provided just a basic config anyways. Anyone can still install
the package manually and enable it in his/her personal config.

core/prelude-editor.el

@@ -275,16 +275,6 @@ Will only occur if prelude-whitespace is also enabled."
 (setq bookmark-default-file (expand-file-name "bookmarks" prelude-savefile-dir)
       bookmark-save-flag 1)
 
-;; load yasnippet
-(require 'yasnippet)
-(add-to-list 'yas-snippet-dirs prelude-snippets-dir)
-(add-to-list 'yas-snippet-dirs prelude-personal-snippets-dir)
-(yas-global-mode 1)
-
-;; term-mode does not play well with yasnippet
-(add-hook 'term-mode-hook (lambda ()
-                            (yas-minor-mode -1)))
-
 ;; projectile is a project management mode
 (require 'projectile)
 (setq projectile-cache-file (expand-file-name  "projectile.cache" prelude-savefile-dir))

core/prelude-packages.el

@@ -47,7 +47,7 @@
     guru-mode helm helm-projectile ido-ubiquitous
     key-chord magit melpa rainbow-mode
     smartparens smex solarized-theme undo-tree
-    volatile-highlights yasnippet zenburn-theme)
+    volatile-highlights zenburn-theme)
   "A list of packages to ensure are installed at launch.")
 
 (defun prelude-packages-installed-p ()