Migrate cvp-sanity to Python3

* use print function from future
* convert dict keys and values to list
* do not use bunch imports
* fix requirements mismatch
Related: PROD-33849

Change-Id: Ifecc3a9dcdcfe3243f7dcf2c709a80e9a7c765a1
(cherry picked from commit e32e3f9ea37a24da5365dcef2a13609057b61923)
diff --git a/test_set/cvp-sanity/tests/test_cinder_services.py b/test_set/cvp-sanity/tests/test_cinder_services.py
index 9e13e36..f223d3e 100644
--- a/test_set/cvp-sanity/tests/test_cinder_services.py
+++ b/test_set/cvp-sanity/tests/test_cinder_services.py
@@ -1,3 +1,4 @@
+from builtins import str
 import pytest
 import logging
 
@@ -30,7 +31,7 @@
     cinder_volume = local_salt_client.cmd_any(
         tgt='keystone:server',
         param='. /root/keystonercv3; cinder service-list | grep "volume" |grep -c -v -e "lvm"')
-    backends_num = len(backends_cinder.keys())
+    backends_num = len(list(backends_cinder.keys()))
     assert cinder_volume == str(backends_num), (
         'Number of cinder-volume services ({0}) does not match number of '
         'volume backends ({1}).'.format(cinder_volume, str(backends_num))