Fix password not strong enough for cmd

Also uses strong passwords for cmd/accout_generator.py.

Change-Id: I44486414e075a8abaebf8371c4c94c908f156ea0
Related-Bug: 1448217
diff --git a/tempest/cmd/account_generator.py b/tempest/cmd/account_generator.py
index 64c9b00..2a8fcd3 100755
--- a/tempest/cmd/account_generator.py
+++ b/tempest/cmd/account_generator.py
@@ -349,7 +349,7 @@
                 resources['users'].append({
                     'tenant': tenant,
                     'name': user,
-                    'pass': data_utils.rand_name(),
+                    'pass': data_utils.rand_password(),
                     'prefix': user_group['prefix'],
                     'roles': user_group['roles']
                 })