Update rspec-rails 2.14.0 -> 2.14.1
Update guard-rspec 4.2.0 -> 4.2.3
Update miscellaneous gems:

rails_serve_static_assets 0.0.1 -> 0.0.2
websocket-driver 0.3.1 -> 0.3.2
Bundle redcarpet 3.0.0
Post.published scope
markdown() helper
Display post body as markdown
Display posts on home page