[appveyor] fix create-project phpunit

Author: nicolas-grekas

bin/simple-phpunit

@@ -61,7 +61,9 @@ if (!file_exists("$PHPUNIT_DIR/phpunit-$PHPUNIT_VERSION/phpunit") || md5_file(__
     @mkdir($PHPUNIT_DIR, 0777, true);
     chdir($PHPUNIT_DIR);
     if (file_exists("phpunit-$PHPUNIT_VERSION")) {
-        passthru(sprintf('\\' === DIRECTORY_SEPARATOR ? '(del /S /F /Q %s & rmdir %1$s) >nul': 'rm -rf %s', "phpunit-$PHPUNIT_VERSION"));
+        passthru(sprintf('\\' === DIRECTORY_SEPARATOR ? 'rmdir /S /Q %s > NUL': 'rm -rf %s', "phpunit-$PHPUNIT_VERSION.old"));
+        rename("phpunit-$PHPUNIT_VERSION", "phpunit-$PHPUNIT_VERSION.old");
+        passthru(sprintf('\\' === DIRECTORY_SEPARATOR ? 'rmdir /S /Q %s': 'rm -rf %s', "phpunit-$PHPUNIT_VERSION.old"));
     }
     passthru("$COMPOSER create-project --no-install --prefer-dist --no-scripts --no-plugins --no-progress --ansi phpunit/phpunit phpunit-$PHPUNIT_VERSION \"$PHPUNIT_VERSION.*\"");
     chdir("phpunit-$PHPUNIT_VERSION");