Update install instructions and min package versions.

- Added missing bundler install step
- Updated sass version, see sass/node-sass#653

README.md

@@ -73,8 +73,9 @@ Mac
     * `rvm install ruby-2.2.0`
     * `rvm --default use 2.2.0`
 1. Install [Pygments](http://pygments.org/)
-    * `easy_install pygments`
+    * `sudo easy_install pygments`
 1. Install [RubyGems](https://rubygems.org/) dependencies ([Jekyll](http://jekyllrb.com/) and [Kramdown](http://kramdown.gettalong.org/))
+    * `gem install bundler`
     * `rvm . do bundle install`
 1. Install the [Grunt CLI](http://gruntjs.com/)
     * `npm install -g grunt-cli`

package.json

@@ -30,8 +30,8 @@
     "grunt-contrib-watch": "~0.6.1",
     "grunt-gae": "^0.2.4",
     "grunt-open": "~0.2.3",
-    "grunt-sass": "^0.17.0",
-    "grunt-webfont": "~0.4.8",
+    "grunt-sass": "^1.0.0",
+    "grunt-webfont": "^0.5.4",
     "js-yaml": "^3.2.2",
     "latest-release": "^1.0.0",
     "marked": "^0.3.2",