Do not scaffold _s theme in test

Author: swissspidy

features/theme-update.feature

@@ -3,12 +3,9 @@ Feature: Update WordPress themes
   Scenario: Updating a theme with no version in the WordPress.org directory shouldn't delete the original theme
     Given a WP install
 
-    When I run `wp scaffold underscores wpclitesttheme`
-    Then STDOUT should contain:
-      """
-      Success: Created theme
-      """
-    And the wp-content/themes/wpclitesttheme directory should exist
+    When I run `wp theme install twentytwelve --force`
+    And I run `wp scaffold child-theme wpclitesttheme --parent_theme=twentytwelve`
+    Then the wp-content/themes/wpclitesttheme directory should exist
 
     When I try `wp theme update wpclitesttheme --version=100.0.0`
     Then STDERR should contain: