add a positive condition to tests

Author: Aurélien Joahny

features/search-replace-export.feature

@@ -39,6 +39,10 @@ Feature: Search / replace with file export
       """
       wp_options
       """
+    And STDOUT should contain:
+      """
+      wp_users
+      """
 
     When I run `wp search-replace example.com example.net --skip-columns=option_value --export`
     Then STDOUT should contain:

features/search-replace.feature

@@ -24,6 +24,10 @@ Feature: Do global search/replace
       """
       wp_postmeta
       """
+    And STDOUT should contain:
+      """
+      wp_users
+      """
 
     When I run `wp search-replace foo bar --skip-columns=guid`
     Then STDOUT should not contain: