Fix tests for the new error pages

Author: rafaelfranca

railties/test/application/configuration_test.rb

@@ -1601,7 +1601,7 @@ def create
       assert_equal :raise, ActionController::Parameters.action_on_unpermitted_parameters
 
       post "/posts", post: { "title" => "zomg" }
-      assert_match "We're sorry, but something went wrong", last_response.body
+      assert_match "We’re sorry, but something went wrong", last_response.body
     end
 
     test "config.action_controller.action_on_unpermitted_parameters = :raise is ignored with expect" do

railties/test/application/middleware/exceptions_test.rb

@@ -150,7 +150,7 @@ def index
 
       assert_nothing_raised do
         get("/foo", {}, "HTTPS" => "on")
-        assert_match "The page you were looking for doesn't exist.", last_response.body
+        assert_match "The page you were looking for doesn’t exist.", last_response.body
       end
     end