Merge branch 'friendly-id' into develop-blog

 Installs and configures FriendlyId on the Post model, so that slugs are the Id
 Admin and public Post controllers use FriendlyId.find to lookup posts
Puts Post resource on root path

 modified:   config/routes.rb
Defines a path name for the Post page route

 modified:   config/routes.rb
Changes root url to posts#index action

 modified:   config/routes.rb
Reorders routes so that admin, static pages are matched before Post slugs

 modified:   config/routes.rb
Merge branch 'post-to-root-path' into develop-blog

 Moves Post resource to root path
 Reorders routes so that admin and static pages are matched before Post slugs