Ignore the RiakCache

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

.drone.yml

@@ -85,7 +85,7 @@ pipeline:
     image: nextcloudci/php7.2:php7.2-12
     commands:
       - composer install
-      - ./lib/composer/bin/parallel-lint --exclude lib/composer/jakub-onderka/ --exclude 3rdparty/symfony/polyfill-php70/Resources/stubs/ --exclude 3rdparty/patchwork/utf8/src/Patchwork/Utf8/Bootup/ --exclude 3rdparty/paragonie/random_compat/lib/ --exclude lib/composer/composer/autoload_static.php --exclude 3rdparty/composer/autoload_static.php .
+      - ./lib/composer/bin/parallel-lint --exclude lib/composer/jakub-onderka/ --exclude 3rdparty/symfony/polyfill-php70/Resources/stubs/ --exclude 3rdparty/patchwork/utf8/src/Patchwork/Utf8/Bootup/ --exclude 3rdparty/paragonie/random_compat/lib/ --exclude lib/composer/composer/autoload_static.php --exclude 3rdparty/composer/autoload_static.php --exclude 3rdparty/doctrine/cache/lib/Doctrine/Common/Cache/RiakCache.php .
     when:
       matrix:
         TESTS: syntax-php7.2