fix "filter" callbacks

Author: devpost-mzheng

README.md

@@ -51,5 +51,5 @@ mount OpenSesame::Engine => OpenSesame.mount_prefix
 Place the following in your application_controller:
 
 ```ruby
-before_filter :authenticate_opensesame!
+before_action :authenticate_opensesame!
 ```

app/controllers/open_sesame/sessions_controller.rb

@@ -1,10 +1,10 @@
 module OpenSesame
   class SessionsController < OpenSesame::ApplicationController
 
-    skip_before_filter :authenticate_opensesame!
+    skip_before_action :authenticate_opensesame!, raise: false
     skip_authorization_check if defined?(CanCan)
-    before_filter :attempt_auto_authenticate, :only => :new
-    after_filter :clear_auto_attempt!, :only => :create
+    before_action :attempt_auto_authenticate, :only => :new
+    after_action :clear_auto_attempt!, :only => :create
 
     def new
       if error_message

spec/dummy/app/controllers/application_controller.rb

@@ -1,5 +1,5 @@
 class ApplicationController < ActionController::Base
   protect_from_forgery
 
-  before_filter :authenticate_opensesame!
+  before_action :authenticate_opensesame!
 end