Cleanup checks if cache dir exists to avoid exception

fractalis/cleanup.py

@@ -9,6 +9,8 @@ def janitor():
     file system while Fractalis is running.
     """
     data_dir = os.path.join(app.config['FRACTALIS_TMP_DIR'], 'data')
+    if not os.path.exists(data_dir):
+        return
     cached_files = [f for f in os.listdir(data_dir)
                     if os.path.isfile(os.path.join(data_dir, f))]
     tracked_files = [key.split(':')[1] for key in redis.scan_iter('data:*')]