flow: Update titan benchmarks version

vtr_flow/scripts/download_titan.py

diff --git a/vtr_flow/scripts/download_titan.py b/vtr_flow/scripts/download_titan.py
index 840af89..907e536 100755
--- a/vtr_flow/scripts/download_titan.py
+++ b/vtr_flow/scripts/download_titan.py
@@ -41,7 +41,7 @@
              )
 
     parser.add_argument("--titan_version",
-                        default="1.3.0",
+                        default="1.3.1",
                         help="Titan release version to download")
     parser.add_argument("--vtr_flow_dir",
                         required=True,