Add failing scenario for testing user token change

spec/acceptance_steps/users/authentication_steps.rb

@@ -13,6 +13,10 @@ step "I am signed in as a user" do
   visit test_login_admin_users_path(email: @user.email)
 end
 
+step "I am signed out as a user" do
+  visit destroy_user_session_path
+end
+
 step "I should be signed in as a user through facebook" do
   @user = User.find_by_oauth_token 'fbAuthToken234'
   # For now, actually better to test a signed in response from the server
@@ -27,3 +31,9 @@ step "the newly created user info should be stored in the local storage" do
   page.evaluate_script(%|Qstorage.getItem('user_id')|).should == @user.id
   page.evaluate_script(%|Qstorage.getItem('auth_token')|).should == @user.authentication_token
 end
+
+step "the user authentication token changes" do
+  @user ||= User.first
+  @user.reset_authentication_token!
+  @user.reload
+end