Set default log level to WARNING

This ensures that the only output comes from the container process by
default.

src/ocivm/cli.py

@@ -62,7 +62,7 @@ def parse_args() -> argparse.Namespace:
     )
     parser.add_argument(
         '--log-level',
-        default='INFO',
+        default='WARNING',
         choices=('CRITICAL', 'ERROR', 'WARNING', 'INFO', 'DEBUG'),
         help='Set CLI log level',
     )