Update six upper bound to 1.16.0

rmk135 · rmk135 · commit c23a48c28eba · 2021-07-29T16:18:45.000-04:00
diff --git a/requirements.txt b/requirements.txt
@@ -1 +1 @@
-six>=1.7.0,<=1.15.0
+six>=1.7.0,<=1.16.0
