update for missing link scenario

+ if the link isn't found, don't redirect it, keep it on the same page
+ it should have a status code of 404
+ it should have the form fields as well

+ added page status check

features/homepage.feature

@@ -42,5 +42,8 @@ Feature: Homepage
 
   Scenario: Accessing a nonexistent URL code
     Given I visit the "/aaaaaa" location
-    Then I should be on "/" page
+    Then I should be on "/aaaaaa" page
+    And The status code should be 404
     And I should see the message "Link aaaaaa doesn't exist"
+    And I should see a form field "url"
+    And I should see a "Submit" button