Relax the upper bound after testing the latest one

Author: rayluo

setup.cfg

@@ -52,7 +52,7 @@ install_requires =
     # And we will use the cryptography (X+3).0.0 as the upper bound,
     # based on their latest deprecation policy
     # https://cryptography.io/en/latest/api-stability/#deprecation
-    cryptography>=2.5,<46
+    cryptography>=2.5,<47
 
 
 [options.extras_require]