Make pw-token-gen.py more random

This fix utilizes the urandom method in the os mmodule and provides
more randomness in our generation tool.

Closes-bug: 1732295
Change-Id: I060976d243dfc4ddc7fd67aff36f3a888a0a363e

scripts/pw-token-gen.py

@@ -22,7 +22,6 @@ import random
 import tarfile
 import uuid
 
-from Crypto import Random
 try:
     import yaml
 except ImportError:
@@ -69,7 +68,7 @@ class CredentialGenerator(object):
     @staticmethod
     def _random_bytes():
         """Returns 1024 random bytes of data."""
-        return Random.get_random_bytes(1024)
+        return os.urandom(1024)
 
     def _encode_bytes(self):
         """Builds random strings based on random data.